From 8ecb7f2de283a96522b8ede2ca1b54b18c768062 Mon Sep 17 00:00:00 2001
From: OpenClaw <openclaw@nyx>
Date: Tue, 15 Sep 2026 06:29:11 +0000
Subject: [PATCH] Phrase mode: always-eighths arpeggio/Giuliani, auto meter,
 custom patterns, alternating bass
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- arpeggioGenerator: always 240-tick eighths; auto-derive 3/4 vs 4/4
  from pattern length (remainder heuristic); never stretch the last
  note (fixes the two-octave 2880-tick VexFlow crash in 6/8); rest
  fills built from renderable durations only; new 'custom' pattern
  from digit input (1=root..5=fifth-above-octave); removed meter/rhythm
  config — generator computes its own meter.
- giulianiGenerator: always eighths; meter auto-derived from figure
  length (3v->3/4, 4v->4/4, 5v->4/4+rest, 6v->3/4); fixed pimami
  figure [0,1,2,3,2,1]; added pimai/pmia/pmim figures; alternating
  bass option (even bars voice the fifth as bass); removed the
  quarter-note fallback.
- PhraseTrainer: removed meter/rhythm selects for arpeggio+giuliani;
  custom pattern text input; alternating bass checkbox.
- SettingsTypes: 'custom' arpeggio pattern, customArpeggioPattern,
  giulianiAlternateBass; removed arpeggioRhythm.
- PhraseSheetMusic: minWidthPerBar 420 -> 500 for 16th notes.
- Tests updated for the new invariants + coverage for custom patterns,
  alternating bass, new figures, renderable-tick sweeps (1031 -> 191
  per-file, all green); removed temporary crash_test.test.ts.
---
 src/components/PhraseSheetMusic.tsx |   2 +-
 src/components/PhraseTrainer.tsx    |  54 ++---
 src/music/arpeggioGenerator.test.ts | 106 +++++++--
 src/music/arpeggioGenerator.ts      | 334 ++++++++++++++++++++--------
 src/music/giulianiGenerator.test.ts | 105 ++++++++-
 src/music/giulianiGenerator.ts      | 138 ++++++++----
 src/types/SettingsTypes.ts          |  12 +-
 7 files changed, 561 insertions(+), 190 deletions(-)

diff --git a/src/components/PhraseSheetMusic.tsx b/src/components/PhraseSheetMusic.tsx
index 9f516ee..ecfc6ee 100644
--- a/src/components/PhraseSheetMusic.tsx
+++ b/src/components/PhraseSheetMusic.tsx
@@ -109,7 +109,7 @@ export const PhraseSheetMusic: React.FC<PhraseSheetMusicProps> = ({
     // horizontal room than quarters) so narrow screens wrap into more rows
     // instead of clipping notes.
     const densestTick = Math.min(...events.filter(e => e.pitch).map(e => e.durationTicks), 1920);
-    const minWidthPerBar = densestTick <= 120 ? 420 : densestTick <= 240 ? 330 : 240;
+    const minWidthPerBar = densestTick <= 120 ? 500 : densestTick <= 240 ? 330 : 240;
     const barsPerRow = Math.max(1, Math.min(4, Math.floor((width - 40) / minWidthPerBar)));
     const rowCount = Math.max(1, Math.ceil(totalBars / barsPerRow));
     const isGrand = clef === 'grand';
diff --git a/src/components/PhraseTrainer.tsx b/src/components/PhraseTrainer.tsx
index 7d54d93..aef5be7 100644
--- a/src/components/PhraseTrainer.tsx
+++ b/src/components/PhraseTrainer.tsx
@@ -193,16 +193,18 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                 }, pool);
             }
             if (phrase.material === 'giuliani') {
+                // Meter is auto-derived inside the generator from the figure
+                // length (always eighths) — the user no longer picks a meter.
                 return generateGiulianiStudy({
                     keyTonic: phrase.keyTonic,
                     keyMode: (isMode(phrase.keyMode) ? phrase.keyMode : 'major') as ModeId,
                     pattern: phrase.giulianiPattern,
-                    meter: { numerator: phrase.meterNumerator, denominator: 4 },
                     tuningId: settings.tuningId,
                     bars: phrase.giulianiBars,
                     chordSelection: phrase.arpeggioChordSelection as string[],
                     seed: melodySeed,
                     allowedStrings: pf.strings,
+                    alternateBass: phrase.giulianiAlternateBass ?? false,
                 }, pool);
             }
             if (phrase.material === 'arpeggio') {
@@ -212,11 +214,10 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                     degree: (phrase.arpeggioDegree as ArpeggioDegree) || 'I',
                     pattern: phrase.arpeggioPattern,
                     coverage: phrase.arpeggioCoverage,
-                    meter: { numerator: phrase.meterNumerator, denominator: 4 },
                     bars: phrase.arpeggioBars,
                     progression: phrase.arpeggioProgression,
                     chordSelection: phrase.arpeggioChordSelection as ArpeggioDegree[],
-                    rhythm: phrase.arpeggioRhythm,
+                    customPattern: phrase.customArpeggioPattern,
                     seed: melodySeed,
                 }, pool);
             }
@@ -233,9 +234,9 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
         }, [phrase.material, phrase.keyTonic, phrase.keyMode, phrase.bars, phrase.meterNumerator,
             phrase.rhythmLevel, phrase.scaleDirection, phrase.scaleCoverage, phrase.scaleRhythm, phrase.libraryId,
             phrase.arpeggioDegree, phrase.arpeggioPattern, phrase.arpeggioCoverage,
-            phrase.arpeggioBars, phrase.arpeggioProgression, phrase.arpeggioRhythm,
+            phrase.arpeggioBars, phrase.arpeggioProgression,
             phrase.arpeggioChordSelection, melodySeed,
-            phrase.giulianiPattern, phrase.giulianiBars,
+            phrase.giulianiPattern, phrase.giulianiBars, phrase.giulianiAlternateBass,
             melodySeed, pool, importedScore]);
 
         const fullScore: Result<Score> | null = useMemo(() => {
@@ -651,9 +652,24 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                                 <option value="121321">1-2-1-3-2-1</option>
                                                 <option value="15453">1-5-4-5-3-5</option>
                                                 <option value="132532">1-3-2-5-3-2</option>
+                                                <option value="custom">Custom…</option>
                                             </optgroup>
                                         </select>
                                     </label>
+                                    {phrase.arpeggioPattern === 'custom' && (
+                                        <label>Custom pattern
+                                            <input
+                                                type="text"
+                                                value={phrase.customArpeggioPattern || ''}
+                                                onChange={e => setPhrase({ customArpeggioPattern: e.target.value.replace(/[^1-5]/g, '') })}
+                                                placeholder="e.g. 1321"
+                                                style={{ width: '90px' }}
+                                            />
+                                            <span style={{ fontSize: '11px', opacity: 0.7, display: 'block' }}>
+                                                Digits: 1=root, 2=third, 3=fifth, 4=octave, 5=fifth-above-octave
+                                            </span>
+                                        </label>
+                                    )}
                                     <label>Coverage
                                         <select value={phrase.arpeggioCoverage} onChange={e => setPhrase({ arpeggioCoverage: e.target.value as PhraseSettings['arpeggioCoverage'] })}>
                                             <option value="one-octave">One octave</option>
@@ -700,19 +716,6 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                             })}
                                         </div>
                                     </div>
-                                    <label>Rhythm
-                                        <select value={phrase.arpeggioRhythm} onChange={e => setPhrase({ arpeggioRhythm: e.target.value as PhraseSettings['arpeggioRhythm'] })}>
-                                            <option value="quarters">Quarter notes</option>
-                                            <option value="eighths">Eighth notes</option>
-                                        </select>
-                                    </label>
-                                    <label>Meter
-                                        <select value={phrase.meterNumerator} onChange={e => setPhrase({ meterNumerator: Math.max(3, Math.min(6, Number(e.target.value))) as 3 | 4 | 6 })}>
-                                            <option value={4}>4/4</option>
-                                            <option value={3}>3/4</option>
-                                            <option value={6}>6/8</option>
-                                        </select>
-                                    </label>
                                 </>
                             )}
 
@@ -730,15 +733,16 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                             {[1, 2, 4, 6, 8].map(b => <option key={b} value={b}>{b} bars</option>)}
                                         </select>
                                     </label>
-                                    <label>Meter
-                                        <select value={phrase.meterNumerator} onChange={e => setPhrase({ meterNumerator: Math.max(3, Math.min(6, Number(e.target.value))) as 3 | 4 | 6 })}>
-                                            <option value={4}>4/4</option>
-                                            <option value={3}>3/4</option>
-                                            <option value={6}>6/8</option>
-                                        </select>
+                                    <label style={{ display: 'flex', flexDirection: 'row', alignItems: 'center', gap: '6px' }}>
+                                        <input
+                                            type="checkbox"
+                                            checked={phrase.giulianiAlternateBass ?? false}
+                                            onChange={e => setPhrase({ giulianiAlternateBass: e.target.checked })}
+                                        />
+                                        Alternating bass (fifth on even bars)
                                     </label>
                                     <span style={{ fontSize: '11px', opacity: 0.7, alignSelf: 'center' }}>
-                                        Chords: from the arpeggio chord pool; voicing enforced (bass + upper strings).
+                                        Meter is derived from the pattern; chords come from the arpeggio chord pool; voicing enforced (bass + upper strings).
                                     </span>
                                 </>
                             )}
diff --git a/src/music/arpeggioGenerator.test.ts b/src/music/arpeggioGenerator.test.ts
index 4f3705c..8ae4cd5 100644
--- a/src/music/arpeggioGenerator.test.ts
+++ b/src/music/arpeggioGenerator.test.ts
@@ -18,8 +18,9 @@ describe('generateArpeggio', () => {
         expect(r.ok).toBe(true);
         if (!r.ok) return;
         const ev = scoreEvents(r.value);
-        // C-E-G-C: 4 notes, quarter each (plus final extension)
-        const midis = ev.map(e => e.pitch!.midi);
+        // C-E-G-C as eighths (always 240 ticks now) plus a rest fill in the
+        // auto-derived bar.
+        const midis = ev.filter(e => e.pitch).map(e => e.pitch!.midi);
         expect(midis).toEqual([48, 52, 55, 60]);
         expect(validateScore(r.value)).toEqual([]);
         expect(r.value.title).toContain('Arpeggio');
@@ -30,7 +31,7 @@ describe('generateArpeggio', () => {
         const r = generateArpeggio({ ...base, degree: 'I', pattern: 'down', coverage: 'one-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const midis = scoreEvents(r.value).map(e => e.pitch!.midi);
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
         expect(midis).toEqual([60, 55, 52, 48]);
     });
 
@@ -38,7 +39,7 @@ describe('generateArpeggio', () => {
         const r = generateArpeggio({ ...base, degree: 'I', pattern: 'updown', coverage: 'one-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const midis = scoreEvents(r.value).map(e => e.pitch!.midi);
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
         // ascend C-E-G-C then descend back to C; only one C5 (turning point)
         expect(midis).toEqual([48, 52, 55, 60, 55, 52, 48]);
         expect(midis.filter(m => m === 60)).toHaveLength(1);
@@ -48,7 +49,7 @@ describe('generateArpeggio', () => {
         const r = generateArpeggio({ ...base, degree: 'I', pattern: '1235', coverage: 'one-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const midis = scoreEvents(r.value).map(e => e.pitch!.midi);
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
         expect(midis).toEqual([48, 52, 55, 60]);
     });
 
@@ -56,14 +57,14 @@ describe('generateArpeggio', () => {
         const r = generateArpeggio({ ...base, degree: 'I', pattern: 'up', coverage: 'two-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const midis = scoreEvents(r.value).map(e => e.pitch!.midi);
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
         expect(midis).toEqual([48, 52, 55, 60, 64, 67, 72]);
     });
     it('spells the dominant triad G-B-D in C major', () => {
         const r = generateArpeggio({ ...base, degree: 'V', pattern: 'up', coverage: 'one-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const pcs = scoreEvents(r.value).map(e => e.pitch!.midi % 12);
+        const pcs = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi % 12);
         expect(pcs).toEqual([7, 11, 2, 7]); // G B D G
     });
 
@@ -71,7 +72,7 @@ describe('generateArpeggio', () => {
         const r = generateArpeggio({ ...base, degree: 'vii0', pattern: 'up', coverage: 'one-octave' }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const pcs = scoreEvents(r.value).map(e => e.pitch!.midi % 12);
+        const pcs = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi % 12);
         expect(pcs).toEqual([11, 2, 5, 11]); // B D F B
     });
 
@@ -101,8 +102,9 @@ describe('generateArpeggio — sequence mode', () => {
         // bar boundaries: each bar starts on a chord root? (not enforced) — but ticks align
         const ev = scoreEvents(r.value);
         expect(validateScore(r.value)).toEqual([]);
-        // 4 beats per bar × 4 bars = 16 notes in quarters mode
-        expect(ev.length).toBe(16);
+        // Auto meter from a 4-note path (960 ticks): 3/4 wins (remainder 480
+        // vs 960 in 4/4) → 6 eighths per bar × 4 bars = 24
+        expect(ev.length).toBe(24);
         // deterministic
         const r2 = generateArpeggio({ ...base, degree: 'I', pattern: 'up', coverage: 'one-octave', bars: 4, progression: 'functional', seed: 7 }, pool);
         expect(r2.ok && JSON.stringify(scoreEvents(r2.value)) === JSON.stringify(ev)).toBe(true);
@@ -116,12 +118,13 @@ describe('generateArpeggio — sequence mode', () => {
         expect(syms).toEqual(['C', 'Dm', 'Em', 'F', 'G', 'Am', 'Bdim']);
     });
 
-    it('eighths rhythm doubles notes per bar', () => {
-        const r = generateArpeggio({ ...base, degree: 'I', pattern: 'up', coverage: 'one-octave', bars: 2, progression: 'functional', rhythm: 'eighths', seed: 3 }, pool);
+    it('eighths fill each bar (always-eighths rhythm)', () => {
+        const r = generateArpeggio({ ...base, degree: 'I', pattern: 'up', coverage: 'one-octave', bars: 2, progression: 'functional', seed: 3 }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
         const ev = scoreEvents(r.value);
-        expect(ev.length).toBe(16); // 2 bars × 4 beats × 2
+        // Auto meter from a 4-note path: 3/4 → 6 eighths per bar × 2 bars
+        expect(ev.length).toBe(12);
         expect(ev[0].durationTicks).toBe(240);
         expect(validateScore(r.value)).toEqual([]);
     });
@@ -136,3 +139,80 @@ describe('generateArpeggio — sequence mode', () => {
         }
     });
 });
+
+describe('generateArpeggio — always-eighths + custom pattern', () => {
+    it('auto-derives 3/4 for a 4-note path (remainder 480 < 960)', () => {
+        const r = generateArpeggio({ ...base, degree: 'I', pattern: 'up', coverage: 'one-octave' }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        expect(r.value.meter).toEqual({ numerator: 3, denominator: 4 });
+        const ev = scoreEvents(r.value);
+        for (const e of ev.filter(x => x.pitch)) expect(e.durationTicks).toBe(240);
+        // 4 notes fill 960 of the 1440-tick bar; remainder is a 480 rest
+        const rest = ev.find(e => e.pitch === null);
+        expect(rest).toBeDefined();
+        expect(rest!.durationTicks).toBe(480);
+        expect(rest!.startTick).toBe(960);
+    });
+
+    it('auto-derives 4/4 for a 6-note path (remainder 480 < 480? no — 6×240=1440 fits 3/4)', () => {
+        // 1321 figure → 4 notes; use 121321 → 6 notes = 1440 ticks = 3/4 exact
+        const r = generateArpeggio({ ...base, degree: 'I', pattern: '121321', coverage: 'one-octave' }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        expect(r.value.meter).toEqual({ numerator: 3, denominator: 4 });
+        const ev = scoreEvents(r.value).filter(e => e.pitch);
+        expect(ev.length).toBe(6);
+        expect(ev.every(e => e.durationTicks === 240)).toBe(true);
+    });
+
+    it('never stretches the last note (the old 2880-tick crash)', () => {
+        const ev = scoreEvents(
+            (generateArpeggio({ ...base, degree: 'I', pattern: 'updown', coverage: 'two-octave' }, pool) as { ok: true; value: import('../score/model').Score }).value
+        );
+        const RENDERABLE = [120, 240, 360, 480, 720, 960, 1440, 1920];
+        for (const e of ev) expect(RENDERABLE).toContain(e.durationTicks);
+    });
+
+    it('builds a custom pattern from digits (1321 = root-fifth-third-root)', () => {
+        const r = generateArpeggio({ ...base, degree: 'I', pattern: 'custom', customPattern: '1321', coverage: 'one-octave' }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
+        expect(midis).toEqual([48, 55, 52, 48]); // C G E C
+    });
+
+    it('digit 5 reaches the fifth above the octave', () => {
+        const r = generateArpeggio({ ...base, degree: 'I', pattern: 'custom', customPattern: '15', coverage: 'one-octave' }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        const midis = scoreEvents(r.value).filter(e => e.pitch).map(e => e.pitch!.midi);
+        expect(midis).toEqual([48, 67]); // C + G above the octave C
+    });
+
+    it('rejects invalid custom patterns cleanly', () => {
+        const empty = generateArpeggio({ ...base, degree: 'I', pattern: 'custom', coverage: 'one-octave' }, pool);
+        expect(empty.ok).toBe(false);
+        const bad = generateArpeggio({ ...base, degree: 'I', pattern: 'custom', customPattern: '179', coverage: 'one-octave' }, pool);
+        expect(bad.ok).toBe(false);
+    });
+
+    it('sweep: every pattern × degree × coverage produces only renderable ticks', () => {
+        const RENDERABLE = [120, 240, 360, 480, 720, 960, 1440, 1920];
+        const patterns = ['up', 'down', 'updown', '1235', '1321', '1325', '1535', '12353', '121321', '1353', '15453', '132532'] as const;
+        const degrees = ['I', 'ii', 'iii', 'IV', 'V', 'vi', 'vii0'] as const;
+        for (const pattern of patterns) {
+            for (const degree of degrees) {
+                for (const coverage of ['one-octave', 'two-octave'] as const) {
+                    const r = generateArpeggio({ ...base, degree, pattern, coverage }, pool);
+                    expect(r.ok).toBe(true);
+                    if (!r.ok) continue;
+                    const ev = scoreEvents(r.value);
+                    expect(ev.length).toBeGreaterThan(0);
+                    for (const e of ev) expect(RENDERABLE).toContain(e.durationTicks);
+                    expect(validateScore(r.value)).toEqual([]);
+                }
+            }
+        }
+    });
+});
diff --git a/src/music/arpeggioGenerator.ts b/src/music/arpeggioGenerator.ts
index b8bf432..a9a12d3 100644
--- a/src/music/arpeggioGenerator.ts
+++ b/src/music/arpeggioGenerator.ts
@@ -7,6 +7,9 @@
  * (one or two octaves). Chord tones are spelled via the key's degree
  * spelling (same machinery as melody/scale generators), so spelling and
  * validation match the Phrase Mode invariants exactly.
+ *
+ * Arpeggio mode is ALWAYS eighths (240 ticks per note). Meter is auto-derived
+ * from the pattern length — the user no longer picks rhythm or meter.
  */
 import { PPQ, validateScore, type Result, type Score, type ScoreEvent } from '../score/model';
 import { keyFor, type KeyContext, type ModeId } from './scales';
@@ -25,12 +28,11 @@ export type ArpeggioPattern =
     | '121321' // rolling thirds (root-third-root-fifth-third-root)
     | '1353'   // root-third-fifth-third
     | '15453'  // root-octave-fifth-octave-fifth-octave
-    | '132532';// long broken-chord wave
+    | '132532' // long broken-chord wave
+    | 'custom'; // user-defined pattern from customPattern digits
 export type ArpeggioCoverage = 'one-octave' | 'two-octave';
 /** How the chord per bar is chosen in sequence mode. */
 export type ArpeggioProgression = 'random' | 'functional' | 'diatonic-cycle';
-/** Rhythm density for arpeggio sequences. */
-export type ArpeggioRhythm = 'quarters' | 'eighths';
 
 export interface ArpeggioConfig {
     readonly keyTonic: string;
@@ -38,16 +40,17 @@ export interface ArpeggioConfig {
     readonly degree: ArpeggioDegree;
     readonly pattern: ArpeggioPattern;
     readonly coverage: ArpeggioCoverage;
-    readonly meter: { readonly numerator: 3 | 4 | 6; readonly denominator: 4 };
     /** Sequence mode: bars > 1 with chord progression selection. */
     readonly bars?: number;
     readonly progression?: ArpeggioProgression;
-    readonly rhythm?: ArpeggioRhythm;
     /** Restrict progression chords to these degrees (empty = all 7).
      *  The first bar always uses `degree` if it is in the selection. */
     readonly chordSelection?: readonly ArpeggioDegree[];
     /** Seed for progression selection (deterministic). */
     readonly seed?: number;
+    /** User-defined custom pattern digits (1-indexed: 1=root, 2=third, 3=fifth,
+     *  4=octave, 5=fifth-above-octave). Only used when pattern === 'custom'. */
+    readonly customPattern?: string;
 }
 
 /** Degree index (0-based) into the scale for each arpeggio degree label. */
@@ -69,17 +72,14 @@ export const PATTERN_LABELS: Record<ArpeggioPattern, string> = {
     '1353': '1-3-5-3',
     '15453': '1-5-4-5-3-5',
     '132532': '1-3-2-5-3-2',
+    'custom': 'Custom…',
 };
 
 /**
- * Giuliani figures — NOTE sequences (not fingerings): the thumb (p) always
- * takes the bass/root, the remaining notes ride the upper chord tones.
- * Indices into the octave cycle [0=root, 1=third, 2=fifth, 3=octave]; the
- * figure repeats with an ascending octave shift per repetition (the bass
- * stays in place — like the Maestoso studies).
+ * Broken-chord figures — NOTE sequences (not fingerings): the bass takes the
+ * root, the remaining notes ride the upper chord tones.
+ * Indices into the octave cycle [0=root, 1=third, 2=fifth, 3=octave].
  */
-// Broken-chord figures — NOTE sequences on the cycle [0=root, 1=third,
-// 2=fifth, 3=octave]; register ascends per repetition.
 const BROKEN_FIGURES: Record<string, number[]> = {
     '1321': [0, 2, 1, 0],
     '1325': [0, 2, 1, 3],
@@ -91,6 +91,16 @@ const BROKEN_FIGURES: Record<string, number[]> = {
     '132532': [0, 2, 1, 3, 2, 1],
 };
 
+/**
+ * Renderable note durations — subset of VexFlow duration codes the
+ * PhraseSheetMusic renderer accepts. ALL generated durations MUST be in this
+ * set, otherwise the renderer produces ghost slots and crashes or misaligns.
+ */
+const RENDERABLE_NOTE_TICKS = new Set([120, 240, 360, 480, 720, 960, 1440, 1920]);
+
+/** Descending renderable durations for rest fills (largest first). */
+const REST_FILL_TICKS = [1920, 1440, 960, 720, 480, 240];
+
 /** pc of a spelled degree (step letter + alter). */
 const degreePc = (d: { step: StepLetter; alter: number }): number =>
     (LETTER_PC[STEP_LETTERS.indexOf(d.step)] + d.alter + 144) % 12;
@@ -128,6 +138,29 @@ function spellInKey(key: KeyContext, midi: number): { step: StepLetter; alter: n
     return { step: d.step, alter: d.alter, octave };
 }
 
+/**
+ * Auto-derive a meter (3/4 or 4/4) from the number of eighths in the phrase.
+ * Always returns 3/4 or 4/4 — 6/8 is never used for arpeggios since it can
+ * produce non-renderable tick sizes with some pattern lengths.
+ *
+ * For N notes at 240 ticks each:
+ *   Try 4/4: bars4 = ceil(N*240 / 1920), remainder4 = bars4*1920 - N*240
+ *   Try 3/4: bars3 = ceil(N*240 / 1440), remainder3 = bars3*1440 - N*240
+ *   Pick the one with smaller remainder (fewer bars as tiebreaker).
+ */
+export function autoArpeggioMeter(noteCount: number): { numerator: 4 | 3; denominator: 4 } {
+    const totalTicks = noteCount * 240;
+    const bars4 = Math.ceil(totalTicks / 1920);
+    const remainder4 = bars4 * 1920 - totalTicks;
+    const bars3 = Math.ceil(totalTicks / 1440);
+    const remainder3 = bars3 * 1440 - totalTicks;
+
+    if (remainder3 < remainder4) return { numerator: 3, denominator: 4 };
+    if (remainder4 < remainder3) return { numerator: 4, denominator: 4 };
+    // equal remainders → prefer fewer bars
+    return bars3 <= bars4 ? { numerator: 3, denominator: 4 } : { numerator: 4, denominator: 4 };
+}
+
 /**
  * Build the arpeggio path: chord tones ascending from the lowest available
  * root (degree tone) that allows a full one/two-octave cycle in the pool.
@@ -193,10 +226,10 @@ function buildPath(key: KeyContext, degreeIndex: number, pool: number[], coverag
             return path;
         }
         default: {
-            // Giuliani figure: cycle [root, third, fifth, octave] with the
+            // Broken-chord figure: cycle [root, third, fifth, octave] with the
             // figure selecting cycle positions per note; the octave wraps so
-            // e.g. p-i-m over C-E-G becomes C E G | C' E' G' ... (ascending
-            // octave register shift every figure repetition).
+            // e.g. 1321 over C-E-G becomes C G E C' ... (ascending octave
+            // register shift every figure repetition).
             const figure = BROKEN_FIGURES[pattern];
             // 4-note cycle per octave: root, third, fifth, octave
             const cycleOct = (oct: number): number[] => [
@@ -215,6 +248,131 @@ function buildPath(key: KeyContext, degreeIndex: number, pool: number[], coverag
     }
 }
 
+/**
+ * Parse custom pattern digits into cycle indices (0-based).
+ * Digits are 1-indexed: 1=root, 2=third, 3=fifth, 4=octave, 5=fifth-above-octave.
+ * Returns null for empty/invalid input.
+ */
+function parseCustomPattern(digits: string): number[] | null {
+    if (!digits || digits.trim().length === 0) return null;
+    const result: number[] = [];
+    for (const ch of digits.trim()) {
+        const n = parseInt(ch, 10);
+        if (isNaN(n) || n < 1 || n > 5) return null;
+        // Map 1→0 (root), 2→1 (third), 3→2 (fifth), 4→3 (octave), 5→4 (fifth above octave)
+        result.push(n - 1);
+    }
+    return result.length > 0 ? result : null;
+}
+
+/**
+ * Build a custom path from 0-based digit indices using the one-octave cycle
+ * [root, third, fifth, octave] (index 4 = fifth above the octave).
+ */
+function buildCustomPath(
+    base: number[],
+    pattern: number[],
+    octavesWanted: number,
+    pool: number[],
+): number[] | null {
+    const cycleOct = (oct: number): number[] => [
+        base[0] + 12 * oct, base[1] + 12 * oct, base[2] + 12 * oct, base[0] + 12 * (oct + 1),
+    ];
+
+    const path: number[] = [];
+    for (let oct = 0; oct < octavesWanted; oct++) {
+        const c = cycleOct(oct);
+        // Extend the cycle for digit 5: fifth above the octave (+7 semitones).
+        const extended = [...c, c[3] + 7];
+        for (const idx of pattern) {
+            const note = extended[idx];
+            if (note === undefined) continue;
+            if (oct > 0 && !pool.includes(note)) continue;
+            path.push(note);
+        }
+    }
+    return path.length > 0 ? path : null;
+}
+
+/**
+ * Build the path for one chord (degree), honouring built-in patterns and the
+ * user-defined custom pattern. Returns null when the chord cannot be voiced
+ * in the playable pool.
+ */
+function pathForChord(
+    key: KeyContext,
+    degreeIndex: number,
+    pool: number[],
+    coverage: ArpeggioCoverage,
+    pattern: ArpeggioPattern,
+    customDigits: number[] | null,
+): number[] | null {
+    if (pattern === 'custom') {
+        if (!customDigits) return null;
+        const tones = chordTonesInPool(key, degreeIndex, pool);
+        if (tones.length < 3) return null;
+        const rootPc = degreePc(key.degrees[degreeIndex]);
+        const roots = tones.filter(m => ((m % 12) + 12) % 12 === rootPc);
+        const octavesWanted = coverage === 'one-octave' ? 1 : 2;
+        for (const root of roots) {
+            // chord tones >= root within one octave, including the octave
+            const cycle: number[] = [];
+            for (const midi of tones) {
+                if (midi >= root && midi <= root + 12) cycle.push(midi);
+            }
+            if (!cycle.includes(root + 12) && pool.includes(root + 12)) cycle.push(root + 12);
+            cycle.sort((a, b) => a - b);
+            if (cycle.length < 3 || cycle[0] !== root) continue;
+            const p = buildCustomPath(cycle, customDigits, octavesWanted, pool);
+            if (p) return p;
+        }
+        return null;
+    }
+    return buildPath(key, degreeIndex, pool, coverage, pattern);
+}
+
+/**
+ * Emit one eighth-note event with key-aware spelling.
+ * Returns false when the midi note cannot be spelled in this key.
+ */
+function pushNote(
+    events: ScoreEvent[],
+    key: KeyContext,
+    midi: number,
+    startTick: number,
+    id: string,
+): boolean {
+    const spelled = spellInKey(key, midi);
+    if (!spelled) return false;
+    events.push({
+        id,
+        startTick,
+        durationTicks: 240,
+        pitch: { midi, ...spelled },
+    });
+    return true;
+}
+
+/**
+ * Fill the tail of the material (after the last note) with rests built from
+ * RENDERABLE durations only. Splits the gap greedily, largest duration first.
+ */
+function pushRestFill(events: ScoreEvent[], fromTick: number, untilTick: number): void {
+    let cursor = fromTick;
+    while (cursor < untilTick) {
+        const gap = untilTick - cursor;
+        const dur = REST_FILL_TICKS.find(d => d <= gap);
+        if (!dur) break; // gap smaller than an eighth — should not happen
+        events.push({
+            id: `r${events.length}`,
+            startTick: cursor,
+            durationTicks: dur,
+            pitch: null, // rest
+        });
+        cursor += dur;
+    }
+}
+
 export function generateArpeggio(
     config: ArpeggioConfig,
     eligiblePitches: number[],
@@ -228,10 +386,7 @@ export function generateArpeggio(
     const coverage = config.coverage;
 
     // ---- Chord sequence ----------------------------------------------------
-    // Single-bar mode: the chosen degree for all bars (bars is 1).
-    // Sequence mode: one chord per bar, chosen by progression rule.
     const degreeIndices: number[] = [];
-    // Sequence chord pool: user selection (restricted to it) or all 7.
     const sel = (config.chordSelection ?? []).filter(d => d in DEGREE_INDEX).map(d => DEGREE_INDEX[d as ArpeggioDegree]);
     const pool7 = sel.length > 0 ? Array.from(new Set(sel)).sort((a, b) => a - b) : [0, 1, 2, 3, 4, 5, 6];
     if (bars === 1) {
@@ -241,8 +396,6 @@ export function generateArpeggio(
         const pick = <T,>(arr: T[]): T => arr[Math.floor(rng() * arr.length)];
         for (let b = 0; b < bars; b++) {
             if (b === 0) {
-                // First bar: a random chord FROM THE SELECTION — fixed starts
-                // repeated the exercise identically every time.
                 degreeIndices.push(pool7.includes(DEGREE_INDEX[config.degree]) && rng() < 0.34
                     ? DEGREE_INDEX[config.degree]
                     : pick(pool7));
@@ -250,20 +403,10 @@ export function generateArpeggio(
             }
             const prev = degreeIndices[b - 1];
             if (config.progression === 'diatonic-cycle') {
-                // Next diatonic degree that is also in the selection
                 let next = (prev + 1) % 7;
                 for (let tries = 0; tries < 7 && !pool7.includes(next); tries++) next = (next + 1) % 7;
                 degreeIndices.push(next);
             } else if (config.progression === 'functional') {
-                // Simple tonal function rules (major-oriented; mirrored for
-                // minor by degree relationships below):
-                //   I   -> {IV, V, vi}
-                //   ii  -> {V}
-                //   iii -> {IV, vi}
-                //   IV  -> {I, V}
-                //   V   -> {I, vi}
-                //   vi  -> {ii, IV}
-                //   vii -> {I}
                 const NEXT: Record<number, number[]> = {
                     0: [3, 4, 5],
                     1: [4],
@@ -273,86 +416,85 @@ export function generateArpeggio(
                     5: [1, 3],
                     6: [0],
                 };
-                // functional: honor the selection — filter rule targets by it
                 const targets = (NEXT[prev] ?? [0]).filter(d => pool7.includes(d));
                 degreeIndices.push(pick(targets.length > 0 ? targets : pool7.filter(d => d !== prev)));
             } else {
-                // random: any selected degree, avoid immediate repetition
                 const candidates = pool7.filter(d => d !== prev);
                 degreeIndices.push(pick(candidates.length > 0 ? candidates : pool7));
             }
         }
     }
 
-    // ---- Path per bar: one arpeggio cycle per chord -------------------------
-    const full = config.meter.numerator * PPQ;
-    const perBarSegments: { path: number[]; degreeIndex: number }[] = [];
-    for (const di of degreeIndices) {
-        const path = buildPath(key, di, pool, coverage, pattern);
-        if (!path || path.length === 0) {
-            return {
-                ok: false,
-                error: 'The arpeggio does not fit the playable range — widen the range (strings/fret window) or pick another degree.',
-            };
-        }
-        perBarSegments.push({ path, degreeIndex: di });
+    // ---- Custom pattern digits (only for pattern === 'custom') --------------
+    const customDigits = pattern === 'custom' ? parseCustomPattern(config.customPattern ?? '') : null;
+    if (pattern === 'custom' && !customDigits) {
+        return { ok: false, error: 'Custom pattern is empty or invalid — enter digits like "1321" (1=root, 2=third, 3=fifth, 4=octave).' };
     }
 
-    // ---- Events: fit each segment into one bar ------------------------------
-    const rhythm = config.rhythm ?? 'quarters';
+    // ---- Build the path for the first chord ----------------------------------
+    // All bars share the same pattern, so the path length (and thus meter) is
+    // derived from the first chord's voicing. Sequence mode repeats the path
+    // within each bar, so the meter also derives from the path length itself.
+    const firstPath = pathForChord(key, degreeIndices[0], pool, coverage, pattern, customDigits);
+    if (!firstPath || firstPath.length === 0) {
+        return {
+            ok: false,
+            error: 'The arpeggio does not fit the playable range — widen the range (strings/fret window) or pick another degree.',
+        };
+    }
+    const meter = autoArpeggioMeter(firstPath.length);
+    const notesPerBar = meter.numerator * 2; // 2 eighths per beat
+    const barLength = meter.numerator * PPQ;
+    const noteDur = 240; // always eighths
+
+    // ---- Events: single-chord vs sequence mode --------------------------------
     const events: ScoreEvent[] = [];
     const chordSymbols: (string | null)[] = [];
-    let cursor = 0;
-    for (let b = 0; b < bars; b++) {
-        const { path, degreeIndex } = perBarSegments[b];
-        chordSymbols.push(chordNameFor(key, degreeIndex));
-        if (bars === 1) {
-            // Single-bar mode (v1 behavior): whole path, final note extended
-            // to fill the bar — or, when the path overflows one bar, spread
-            // over the needed bars with the overflow in the last note.
-            const barCount = Math.max(1, Math.ceil((path.length * PPQ) / full));
-            const totalTicks = barCount * full;
-            const lastDuration = PPQ + (totalTicks - path.length * PPQ);
-            path.forEach((midi, n) => {
-                const spelled = spellInKey(key, midi);
-                if (!spelled) return;
-                const dur = n === path.length - 1 ? lastDuration : PPQ;
-                events.push({ id: `a${b}-${n}`, startTick: cursor, durationTicks: dur, pitch: { midi, ...spelled } });
-                cursor += dur;
-            });
-            continue;
-        }
-        // Sequence mode: fit the bar exactly. 'quarters': one note per beat,
-        // cycling up/down through the path. 'eighths': two notes per beat.
-        const slots = rhythm === 'quarters' ? 1 : 2;
-        const notesPerBar = config.meter.numerator * slots;
-        const line: number[] = [];
-        let dir = 1;
-        let lastIdx = 0;
-        while (line.length < notesPerBar) {
-            line.push(path[lastIdx]);
-            if (lastIdx + dir < 0 || lastIdx + dir >= path.length) dir = -dir;
-            else lastIdx += dir;
-        }
-        const noteDur = full / notesPerBar;
-        line.forEach((midi, n) => {
-            const spelled = spellInKey(key, midi);
-            if (!spelled) return;
-            events.push({
-                id: `a${b}-${n}`,
-                startTick: cursor,
-                durationTicks: noteDur,
-                pitch: { midi, ...spelled },
-            });
+
+    if (bars === 1) {
+        // Single-chord mode: the path plays once; any remaining ticks in the
+        // final bar(s) become rests (renderable durations only). The path is
+        // NEVER stretched — durations stay at 240 ticks.
+        const barCount = Math.max(1, Math.ceil((firstPath.length * noteDur) / barLength));
+        chordSymbols.push(chordNameFor(key, degreeIndices[0]));
+
+        let cursor = 0;
+        for (let slot = 0; slot < firstPath.length; slot++) {
+            pushNote(events, key, firstPath[slot], cursor, `a0-${slot}`);
             cursor += noteDur;
-        });
+        }
+        const totalTicks = barCount * barLength;
+        if (cursor < totalTicks) pushRestFill(events, cursor, totalTicks);
+    } else {
+        // Sequence mode: one chord per bar, each bar holds exactly
+        // `notesPerBar` eighths (the path cycles if it is shorter, and is
+        // truncated if longer — with two-octave coverage the auto-derived
+        // meter always gives enough room).
+        let cursor = 0;
+        for (let b = 0; b < bars; b++) {
+            const di = degreeIndices[b];
+            chordSymbols.push(chordNameFor(key, di));
+            const barPath = pathForChord(key, di, pool, coverage, pattern, customDigits);
+            if (!barPath || barPath.length === 0) {
+                return { ok: false, error: `Cannot voice arpeggio for chord ${chordNameFor(key, di)}.` };
+            }
+            for (let n = 0; n < notesPerBar; n++) {
+                pushNote(events, key, barPath[n % barPath.length], cursor, `a${b}-${n}`);
+                cursor += noteDur;
+            }
+        }
+    }
+
+    // ---- Validate all durations are renderable -----------------------------
+    for (const e of events) {
+        if (!RENDERABLE_NOTE_TICKS.has(e.durationTicks)) {
+            return { ok: false, error: `Internal arpeggio error: non-renderable duration ${e.durationTicks} at ${e.id}.` };
+        }
     }
 
     const chordName = `${key.tonic} ${ARPEGGIO_DEGREE_LABELS[config.degree]}`;
     const patternLabel = PATTERN_LABELS[config.pattern];
-    // Single-bar paths can overflow into extra bars (updown/two-octave);
-    // sequence mode always has exactly `bars` measures.
-    const totalMeasures = bars === 1 ? Math.max(1, Math.ceil((cursor) / full)) : bars;
+    const totalMeasures = Math.max(1, Math.ceil(events.reduce((s, e) => Math.max(s, e.startTick + e.durationTicks), 0) / barLength));
     const title = bars === 1
         ? `Arpeggio — ${chordName} (${patternLabel}, ${coverage})`
         : `Arpeggio — ${key.tonic}: ${bars} bars (${config.progression ?? 'functional'})`;
@@ -360,12 +502,12 @@ export function generateArpeggio(
         version: 1,
         id: `arpeggio-${config.keyTonic}-${config.keyMode}-${config.degree}-${config.pattern}-${config.coverage}-${bars}b-${config.progression ?? 'single'}-${config.seed ?? 0}`,
         title,
-        meter: config.meter,
+        meter,
         key: { tonic: config.keyTonic, mode: config.keyMode, signature: key.signature },
         measures: Array.from({ length: totalMeasures }, (_, i) => ({
             number: i + 1,
-            startTick: i * full,
-            durationTicks: full,
+            startTick: i * barLength,
+            durationTicks: barLength,
         })),
         chordSymbols: bars === 1
             // repeat the single chord symbol across the overflow bars
@@ -376,4 +518,4 @@ export function generateArpeggio(
     const problems = validateScore(score);
     if (problems.length > 0) return { ok: false, error: `Internal arpeggio error: ${problems[0]}` };
     return { ok: true, value: score };
-}
+}
\ No newline at end of file
diff --git a/src/music/giulianiGenerator.test.ts b/src/music/giulianiGenerator.test.ts
index 6f6d602..bd9bea1 100644
--- a/src/music/giulianiGenerator.test.ts
+++ b/src/music/giulianiGenerator.test.ts
@@ -9,7 +9,6 @@ for (const open of strings) for (let f = 0; f <= 12; f++) pool.push(open + f);
 const base = {
     keyTonic: 'C',
     keyMode: 'major' as const,
-    meter: { numerator: 4 as const, denominator: 4 as const },
     tuningId: 'standard',
     bars: 4,
     chordSelection: [] as string[],
@@ -23,7 +22,8 @@ describe('generateGiulianiStudy', () => {
         if (!r.ok) return;
         const ev = scoreEvents(r.value);
         expect(r.value.measures.length).toBe(4);
-        expect(ev.length).toBe(4 * 4 * 4); // bars × beats × figure length
+        // 4 voices → 4/4 auto-derived; eighths: 8 notes per bar
+        expect(ev.length).toBe(4 * 8);
         expect(validateScore(r.value)).toEqual([]);
         expect(r.value.title).toContain('Giuliani');
     });
@@ -34,7 +34,7 @@ describe('generateGiulianiStudy', () => {
         if (!r.ok) return;
         // For each repetition of 4 consecutive notes, all midis must differ
         // (distinct cycle positions → distinct pitches within a beat figure)
-        const ev = scoreEvents(r.value);
+        const ev = scoreEvents(r.value).filter(e => e.pitch);
         for (let i = 0; i + 3 < ev.length; i += 4) {
             const four = ev.slice(i, i + 4).map(e => e.pitch!.midi);
             expect(new Set(four).size).toBe(4);
@@ -45,10 +45,10 @@ describe('generateGiulianiStudy', () => {
         const r = generateGiulianiStudy({ ...base, pattern: 'pimamim', seed: 1 }, pool);
         expect(r.ok).toBe(true);
         if (!r.ok) return;
-        const ev = scoreEvents(r.value);
-        // 4/4: figure falls back to quarter-note walk (6-note figure over 4
-        // beats is not renderable in even subdivisions) — 4 bars × 4 quarters
-        expect(ev.length).toBe(16);
+        const ev = scoreEvents(r.value).filter(e => e.pitch);
+        // 6 voices → 3/4 auto-derived; eighths: 6 notes per bar (one cycle)
+        expect(ev.length).toBe(4 * 6);
+        expect(ev.every(e => e.durationTicks === 240)).toBe(true);
         expect(validateScore(r.value)).toEqual([]);
     });
 
@@ -63,3 +63,94 @@ describe('generateGiulianiStudy', () => {
         expect(r.ok).toBe(false); // 4 voices cannot live on one string
     });
 });
+
+describe('generateGiulianiStudy — always-eighths + new patterns', () => {
+    it('all note durations are exactly 240 across every pattern', () => {
+        const patterns = ['pim', 'pima', 'pami', 'aim', 'pimamim', 'pmamim', 'piai', 'pmami', 'pimami', 'pimaia', 'pimai', 'pmia', 'pmim'] as const;
+        for (const p of patterns) {
+            const r = generateGiulianiStudy({ ...base, pattern: p, seed: 1 }, pool);
+            expect(r.ok).toBe(true);
+            if (!r.ok) continue;
+            const ev = scoreEvents(r.value);
+            const RENDERABLE = [120, 240, 360, 480, 720, 960, 1440, 1920];
+            for (const e of ev.filter(x => x.pitch)) expect(e.durationTicks).toBe(240);
+            for (const e of ev.filter(x => x.pitch === null)) expect(RENDERABLE).toContain(e.durationTicks);
+            expect(validateScore(r.value)).toEqual([]);
+        }
+    });
+
+    it('alternating bass puts the fifth degree in the bass on even bars', () => {
+        const r = generateGiulianiStudy({ ...base, pattern: 'pima', seed: 4, bars: 4, alternateBass: true }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        const ev = scoreEvents(r.value).filter(e => e.pitch);
+        const full = 4 * 480; // 4/4 bar
+        // Even bars (0-indexed): first note of each figure cycle is the bass.
+        // Its pc must be the FIFTH of the bar's chord (C major: cycle starts
+        // on I or another diatonic chord; verify bass ≠ root and bass = fifth).
+        for (let bar = 0; bar < 4; bar += 2) {
+            const barEv = ev.filter(e => e.startTick >= bar * full && e.startTick < (bar + 1) * full);
+            expect(barEv.length).toBeGreaterThan(0);
+            const bassMidi = barEv[0].pitch!.midi;
+            const upperPcs = new Set(barEv.slice(1).map(e => e.pitch!.midi % 12));
+            // the bass pc must NOT equal any upper-voice root pc check below;
+            // direct check: bass pc differs from the plain-root voicing
+            const plain = generateGiulianiStudy({ ...base, pattern: 'pima', seed: 4, bars: 4 }, pool);
+            expect(plain.ok).toBe(true);
+            if (!plain.ok) return;
+            const plainEv = scoreEvents(plain.value).filter(e => e.pitch);
+            const plainBass = plainEv.filter(e => e.startTick >= bar * full && e.startTick < (bar + 1) * full)[0];
+            expect(bassMidi % 12).not.toBe(plainBass.pitch!.midi % 12);
+            // and it must be a fifth above the root (7 semitones) — i.e. a
+            // chord tone that is neither root nor third of the upper cycle
+            const bassPc = bassMidi % 12;
+            const rootPc = plainBass.pitch!.midi % 12;
+            // fifth of a diatonic triad: +7 semitones (+6 for the dim chord)
+            expect([6, 7]).toContain((bassPc - rootPc + 12) % 12);
+            void upperPcs;
+        }
+    });
+
+    it('odd bars keep the root bass when alternating is on', () => {
+        const r = generateGiulianiStudy({ ...base, pattern: 'pima', seed: 4, bars: 4, alternateBass: true }, pool);
+        const plain = generateGiulianiStudy({ ...base, pattern: 'pima', seed: 4, bars: 4 }, pool);
+        expect(r.ok && plain.ok).toBe(true);
+        if (!r.ok || !plain.ok) return;
+        const ev = scoreEvents(r.value).filter(e => e.pitch);
+        const plainEv = scoreEvents(plain.value).filter(e => e.pitch);
+        const full = 4 * 480;
+        for (let bar = 1; bar < 4; bar += 2) {
+            const bass = ev.filter(e => e.startTick >= bar * full && e.startTick < (bar + 1) * full)[0];
+            const plainBass = plainEv.filter(e => e.startTick >= bar * full && e.startTick < (bar + 1) * full)[0];
+            expect(bass.pitch!.midi % 12).toBe(plainBass.pitch!.midi % 12);
+        }
+    });
+
+    it('new figure lengths auto-derive the specified meter', () => {
+        const cases: [GiulianiPattern, 3 | 4][] = [
+            ['pim', 3], ['pima', 4], ['pimamim', 3], ['pimai', 4], ['pmia', 4], ['pmim', 4],
+        ];
+        for (const [p, num] of cases) {
+            const r = generateGiulianiStudy({ ...base, pattern: p, seed: 2 }, pool);
+            expect(r.ok).toBe(true);
+            if (!r.ok) continue;
+            expect(r.value.meter.numerator).toBe(num);
+            expect(r.value.meter.denominator).toBe(4);
+        }
+    });
+
+    it('5-voice figures (pimai) fill 4/4 with a trailing 720-tick rest', () => {
+        const r = generateGiulianiStudy({ ...base, pattern: 'pimai', seed: 2, bars: 2 }, pool);
+        expect(r.ok).toBe(true);
+        if (!r.ok) return;
+        const ev = scoreEvents(r.value);
+        const full = 1920;
+        for (let bar = 0; bar < 2; bar++) {
+            const barEv = ev.filter(e => e.startTick >= bar * full && e.startTick < (bar + 1) * full);
+            const rest = barEv.find(e => e.pitch === null);
+            expect(rest).toBeDefined();
+            expect(rest!.startTick).toBe(bar * full + 1200);
+            expect(rest!.durationTicks).toBe(720);
+        }
+    });
+});
diff --git a/src/music/giulianiGenerator.ts b/src/music/giulianiGenerator.ts
index f2ad228..344ddce 100644
--- a/src/music/giulianiGenerator.ts
+++ b/src/music/giulianiGenerator.ts
@@ -10,6 +10,10 @@
  * the root) and V-1 higher strings; each note of the cycle is placed on its
  * designated string at the fret matching the chord tone. Figure repeats
  * over the chord; every bar re-voices (deterministically) so sequences work.
+ *
+ * Rhythm is ALWAYS eighths (240 ticks per note); meter is auto-derived from
+ * the figure length, so odd figure lengths never produce non-renderable
+ * durations.
  */
 import { PPQ, validateScore, type Result, type Score, type ScoreEvent, STEP_LETTERS, LETTER_PC, type StepLetter } from '../score/model';
 import { keyFor, type KeyContext, type ModeId } from './scales';
@@ -25,8 +29,11 @@ export type GiulianiPattern =
     | 'pmamim'   // asymmetric
     | 'piai'     // bass + octave-third (wide spacing)
     | 'pmami'    // bass + fifth-octave-third
-    | 'pimami'   // bass-third-fifth-third (waltz-like)
-    | 'pimaia';  // bass with two upper-voice pairs
+    | 'pimami'   // bass-third-fifth-octave-third-fifth (waltz-like)
+    | 'pimaia'   // bass with two upper-voice pairs
+    | 'pimai'    // p-i-m-a-i
+    | 'pmia'     // p-m-i-a
+    | 'pmim';    // p-m-i-m
 
 export const GIULIANI_PATTERN_LABELS: Record<GiulianiPattern, string> = {
     pim: 'p-i-m (3 voices)',
@@ -39,6 +46,9 @@ export const GIULIANI_PATTERN_LABELS: Record<GiulianiPattern, string> = {
     pmami: 'p-m-a-m-i',
     pimami: 'p-i-m-a-m-i (waltz)',
     pimaia: 'p-i-m-a-i-a',
+    pimai: 'p-i-m-a-i',
+    pmia: 'p-m-i-a',
+    pmim: 'p-m-i-m',
 };
 
 /** Figure voice slots per repetition (indices into the cycle [root, third, fifth, octave]). */
@@ -51,15 +61,17 @@ const FIGURES: Record<GiulianiPattern, number[]> = {
     pmamim: [0, 2, 3, 2, 1, 2],
     piai: [0, 1, 3, 1],
     pmami: [0, 2, 3, 2, 1],
-    pimami: [0, 1, 2, 3, 2],
+    pimami: [0, 1, 2, 3, 2, 1],
     pimaia: [0, 1, 2, 3, 1, 3],
+    pimai: [0, 1, 2, 3, 1],
+    pmia: [0, 2, 1, 3],
+    pmim: [0, 2, 1, 2],
 };
 
 export interface GiulianiConfig {
     readonly keyTonic: string;
     readonly keyMode: ModeId;
     readonly pattern: GiulianiPattern;
-    readonly meter: { readonly numerator: 3 | 4 | 6; readonly denominator: 4 };
     readonly tuningId: string;
     /** Bars (one chord per bar). */
     readonly bars: number;
@@ -69,6 +81,9 @@ export interface GiulianiConfig {
     readonly seed: number;
     /** Deterministic pattern from the practice filter (strings restriction). */
     readonly allowedStrings: readonly number[];
+    /** Alternating bass: even bars (0-indexed) take the fifth degree as the
+     *  bass note instead of the root. Upper voices stay on chord tones. */
+    readonly alternateBass?: boolean;
 }
 
 const DEGREE_INDEX: Record<string, number> = { I: 0, ii: 1, iii: 2, IV: 3, V: 4, vi: 5, 'vii0': 6 };
@@ -98,32 +113,63 @@ function triadPcs(key: KeyContext, degreeIndex: number): ChordTone[] {
     }));
 }
 
+/**
+ * Auto-derive meter from the figure length (always eighths):
+ *   3 voices (240×3=720):  3/4 (2 cycles = 1440, perfect fit)
+ *   4 voices (240×4=960):  4/4 (2 cycles = 1920, perfect fit)
+ *   5 voices (240×5=1200): 4/4 (1 cycle + 720 rest)
+ *   6 voices (240×6=1440): 3/4 (1 cycle = 1440, perfect fit)
+ */
+export function autoGiulianiMeter(figureLength: number): { numerator: 3 | 4; denominator: 4 } {
+    switch (figureLength) {
+        case 3: return { numerator: 3, denominator: 4 };
+        case 4: return { numerator: 4, denominator: 4 };
+        case 5: return { numerator: 4, denominator: 4 };
+        case 6: return { numerator: 3, denominator: 4 };
+        default: {
+            // Fall back to the same remainder heuristic as arpeggios.
+            const totalTicks = figureLength * 240;
+            const bars4 = Math.ceil(totalTicks / 1920);
+            const remainder4 = bars4 * 1920 - totalTicks;
+            const bars3 = Math.ceil(totalTicks / 1440);
+            const remainder3 = bars3 * 1440 - totalTicks;
+            if (remainder3 < remainder4) return { numerator: 3, denominator: 4 };
+            if (remainder4 < remainder3) return { numerator: 4, denominator: 4 };
+            return bars3 <= bars4 ? { numerator: 3, denominator: 4 } : { numerator: 4, denominator: 4 };
+        }
+    }
+}
+
 /**
  * Voice a figure bar: assign each cycle position (root/third/fifth/octave)
  * to a string with a valid fret, bass string lowest. Returns per-slot
  * {stringIndex, fret, midi} or null when impossible with the allowed strings.
+ * When `bassOverridePc` is given, the bass (cycle position 0) uses that pitch
+ * class instead of the root (alternating bass).
  */
 function voiceBar(
     tuning: Tuning,
     chord: ChordTone[],
     pattern: GiulianiPattern,
     allowedStrings: number[],
+    bassOverridePc?: number,
 ): { stringIndex: number; fret: number; midi: number }[] | null {
     const figure = FIGURES[pattern];
     const maxVoice = Math.max(...figure) + 1; // e.g. 3 for p-i-m, 4 for p-i-m-a
-    const bassPc = chord[0].pc;
+    const bassPc = bassOverridePc ?? chord[0].pc;
 
     // Candidate strings sorted low→high for the bass; upper voices fill above.
     const strings = tuning.strings.map((open, idx) => ({ open, idx }));
     const sorted = [...strings].sort((a, b) => a.open - b.open);
     const usable = sorted.filter(s => allowedStrings.length === 0 || allowedStrings.includes(s.idx));
 
-    const octavePcs = [...chord.map(c => c.pc), (chord[0].pc + 12) % 12];
-    // cyclePcs[i] = pitch class of cycle position i
-    const cyclePcs = octavePcs;
+    // cyclePcs[i] = pitch class of cycle position i (0 = bass, 1..3 = upper
+    // chord tones: third, fifth, octave-of-root).
+    const cyclePcs = [...chord.map(c => c.pc), (chord[0].pc + 12) % 12];
+    if (bassOverridePc !== undefined) cyclePcs[0] = bassOverridePc;
 
     const bassCandidates = usable.filter(s => {
-        // bass must be able to reach the root within 12 frets
+        // bass must be able to reach the bass pc within 12 frets
         for (let fret = 0; fret <= 12; fret++) {
             if (((s.open + fret) % 12 + 12) % 12 === bassPc) return true;
         }
@@ -188,13 +234,23 @@ export function generateGiulianiStudy(
     }
 
     // Voice each bar; drop bars that cannot be voiced (rare with full pool).
-    const full = config.meter.numerator * PPQ;
+    const figure = FIGURES[config.pattern];
+    // Meter is ALWAYS auto-derived from the figure length; the user no longer
+    // picks a meter for Giuliani studies.
+    const meter = autoGiulianiMeter(figure.length);
+    const full = meter.numerator * PPQ;
     const events: ScoreEvent[] = [];
     const chordSymbols: (string | null)[] = [];
     const usableBars: { degreeIndex: number; placement: ReturnType<typeof voiceBar> }[] = [];
-    for (const di of degreeIndices) {
+    for (let b = 0; b < degreeIndices.length; b++) {
+        const di = degreeIndices[b];
         const chord = triadPcs(key, di);
-        const placement = voiceBar(tuning, chord, config.pattern, config.allowedStrings as number[]);
+        // Alternating bass: even bars (0-indexed) take the fifth degree as
+        // the bass note instead of the root.
+        const bassOverridePc = config.alternateBass && b % 2 === 0
+            ? chord[2].pc
+            : undefined;
+        const placement = voiceBar(tuning, chord, config.pattern, config.allowedStrings as number[], bassOverridePc);
         if (!placement) continue;
         usableBars.push({ degreeIndex: di, placement });
     }
@@ -202,39 +258,19 @@ export function generateGiulianiStudy(
         return { ok: false, error: 'No bar could be voiced with the current string selection — allow more strings or a lower fret window.' };
     }
 
-    // Rhythm: one note per slot (figure repeats); one figure per beat.
-    const figure = FIGURES[config.pattern];
-    // Renderable note durations only (durationCode subset). Figures with a
-    // length that divides neither 4 nor 3 evenly would produce exotic ticks
-    // (e.g. 96 = 32nd triplets) that the renderer can't spell — snap those
-    // combinations to a safe layout instead of crashing the renderer.
-    const RENDERABLE_NOTE_TICKS = [120, 240, 360, 480, 720, 960];
-    let notesPerBar = config.meter.numerator * figure.length;
-    let noteDur = full / notesPerBar;
-    if (!RENDERABLE_NOTE_TICKS.includes(noteDur)) {
-        // Fall back: one figure per TWO beats (halves the notes per bar),
-        // then per bar, then quarters as last resort.
-        for (const div of [2, 3, 4]) {
-            const cand = full / div;
-            if (cand % figure.length === 0 && RENDERABLE_NOTE_TICKS.includes(cand / figure.length)) {
-                notesPerBar = div * figure.length;
-                noteDur = cand / figure.length;
-                break;
-            }
-        }
-        if (!RENDERABLE_NOTE_TICKS.includes(noteDur)) {
-            // Final fallback: quarter-note walk through the figure (cycling).
-            notesPerBar = config.meter.numerator;
-            noteDur = PPQ;
-        }
-    }
+    // Rhythm: ALWAYS eighths (240 ticks). Each bar holds
+    // `notesPerBar = (bar length / 240)` notes; the figure repeats to fill
+    // the bar. For 3- and 4-voice figures in their derived meter this is a
+    // whole number of repetitions; 5-voice figures in 4/4 leave a 720-tick
+    // rest at the bar end.
+    const notesPerBar = Math.floor((meter.numerator * PPQ) / 240);
+    const fillSlots = Math.floor(notesPerBar / figure.length) * figure.length;
 
     let cursor = 0;
     for (let b = 0; b < usableBars.length; b++) {
         const { degreeIndex, placement } = usableBars[b];
-        if (!placement) continue;
         chordSymbols.push(chordNameFor(key, degreeIndex));
-        for (let n = 0; n < notesPerBar; n++) {
+        for (let n = 0; n < fillSlots; n++) {
             const f = n % figure.length;
             const slot = figure[f];
             const note = placement[slot];
@@ -247,10 +283,24 @@ export function generateGiulianiStudy(
             events.push({
                 id: `g${b}-${n}`,
                 startTick: cursor,
-                durationTicks: noteDur,
+                durationTicks: 240,
                 pitch: { midi: note.midi, step: d.step, alter: d.alter, octave },
             });
-            cursor += noteDur;
+            cursor += 240;
+        }
+        // Rest fill for figure lengths that leave a gap (e.g. 5 voices in 4/4:
+        // one cycle = 1200 ticks, remaining 720 = dotted quarter rest).
+        const barStart = b * full;
+        const barEnd = barStart + full;
+        if (cursor < barEnd) {
+            const gap = barEnd - cursor;
+            events.push({
+                id: `gr${b}`,
+                startTick: cursor,
+                durationTicks: gap,
+                pitch: null,
+            });
+            cursor = barEnd;
         }
     }
 
@@ -259,7 +309,7 @@ export function generateGiulianiStudy(
         version: 1,
         id: `giuliani-${config.keyTonic}-${config.keyMode}-${config.pattern}-${config.bars}b-${config.seed}`,
         title: `Giuliani study — ${key.tonic} ${config.pattern} (${totalBars} bars)`,
-        meter: config.meter,
+        meter,
         key: { tonic: config.keyTonic, mode: config.keyMode, signature: key.signature },
         measures: Array.from({ length: totalBars }, (_, i) => ({
             number: i + 1,
@@ -272,4 +322,4 @@ export function generateGiulianiStudy(
     const problems = validateScore(score);
     if (problems.length > 0) return { ok: false, error: `Internal giuliani error: ${problems[0]}` };
     return { ok: true, value: score };
-}
+}
\ No newline at end of file
diff --git a/src/types/SettingsTypes.ts b/src/types/SettingsTypes.ts
index 0a83ca4..23f060f 100644
--- a/src/types/SettingsTypes.ts
+++ b/src/types/SettingsTypes.ts
@@ -61,14 +61,13 @@ export interface PhraseSettings {
     arpeggioDegree: string; // ArpeggioDegree (single-chord mode / sequence start)
     /** Sequence mode: which degrees may appear (empty = all 7). */
     arpeggioChordSelection: string[];
-    arpeggioPattern: 'up' | 'down' | 'updown' | '1235';
+    arpeggioPattern: 'up' | 'down' | 'updown' | '1235' | 'custom';
     arpeggioCoverage: 'one-octave' | 'two-octave';
     /** Sequence mode: bars per exercise (1 = single chord). */
     arpeggioBars: number;
     arpeggioProgression: 'random' | 'functional' | 'diatonic-cycle';
-    arpeggioRhythm: 'quarters' | 'eighths';
     /** Giuliani study material (own category — voicing-enforced). */
-    giulianiPattern: 'pim' | 'pima' | 'pami' | 'aim' | 'pimamim' | 'pmamim';
+    giulianiPattern: 'pim' | 'pima' | 'pami' | 'aim' | 'pimamim' | 'pmamim' | 'piai' | 'pmami' | 'pimami' | 'pimaia' | 'pimai' | 'pmia' | 'pmim';
     giulianiBars: number;
     /** Phrase-local fret window (guitar/bass) — overrides the note set. */
     fretWindowEnabled: boolean;
@@ -87,6 +86,10 @@ export interface PhraseSettings {
     /** Begin the run as soon as the first note is played (no count-in,
      *  step pace only). */
     autoStartOnNote: boolean;
+    /** Custom arpeggio pattern as raw digits (1=root, 2=third, etc.). */
+    customArpeggioPattern?: string;
+    /** Alternating bass thumb for Giuliani studies. */
+    giulianiAlternateBass?: boolean;
 }
 
 export const DEFAULT_PHRASE_SETTINGS: PhraseSettings = {
@@ -106,7 +109,6 @@ export const DEFAULT_PHRASE_SETTINGS: PhraseSettings = {
     arpeggioCoverage: 'one-octave',
     arpeggioBars: 1,
     arpeggioProgression: 'functional',
-    arpeggioRhythm: 'quarters',
     giulianiPattern: 'pima',
     giulianiBars: 4,
     fretWindowEnabled: false,
@@ -120,6 +122,8 @@ export const DEFAULT_PHRASE_SETTINGS: PhraseSettings = {
     autoContinue: true,
     inputMode: 'mic',
     autoStartOnNote: false,
+    customArpeggioPattern: '',
+    giulianiAlternateBass: false,
 };
 
 export function getPhraseSettings(s: AppSettings): PhraseSettings {