UI reorg: settings grouped by usage frequency

- Filter (key/strings/fret window) collapsed behind Filter button with
  active-count badge; opens the unified TargetNoteControls panel
- Display key signature moved into the filter panel (all modes)
- Instrument + Tuning selects moved into Settings modal (Instrument
  section); removed from footer
- Settings modal restructured into collapsible sections: Instrument,
  Appearance, Audio, Microphone
- Phrase setup panel: removed cross-reference hint texts
- PracticeFilter is now the single source of truth: removed mirrored
  keyTonic/keyMode/fretWindow fields from PhraseSettings
- Dark mode: neutral gray with slight blue tint (was warm brown)

src/components/Controls.tsx

@@ -1,14 +1,11 @@
 import React, { useEffect, useState } from 'react';
-import { Guitar, Music, Gauge } from 'lucide-react';
+import { Gauge, SlidersHorizontal } from 'lucide-react';
-import { TUNINGS, INSTRUMENT_TUNINGS } from '../music/Tunings';
-import { INSTRUMENT_DEFINITIONS } from '../music/InstrumentConfigs';
-
 import { TuningMeter } from './TuningMeter';
 import { TargetNoteControls } from './TargetNoteControls';
 import { MetronomeWidget } from './MetronomeWidget';
 import { phraseRunBus } from '../hooks/phraseRunBus';
 import { useSettings } from '../context/useSettings';
-import { type Difficulty, type RhythmSettings } from '../types/SettingsTypes';
+import { getPracticeFilter, type RhythmSettings } from '../types/SettingsTypes';
 
 
 
@@ -18,35 +15,13 @@ interface ControlsProps {
 
 export const Controls: React.FC<ControlsProps> = ({ currentPitch }) => {
     const { settings, updateSettings } = useSettings();
-    // Alias to minimize refactor, or just use updateSettings. 
     const onUpdateSettings = updateSettings;
     // Phrase run gate: the metronome only ticks while the phrase trainer is
     // counting in / playing (armed by the user toggle, fired by the run).
     const [phraseRunActive, setPhraseRunActive] = useState(false);
     useEffect(() => phraseRunBus.subscribe(setPhraseRunActive), []);
-    const handleTuningChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
+    // Note-filter panel: hidden by default (minimal UI), toggled here.
-        onUpdateSettings({ ...settings, tuningId: e.target.value });
+    const [filtersOpen, setFiltersOpen] = useState(false);
-    };
-
-    const handleInstrumentChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
-        const newInstrumentId = e.target.value;
-        const instDef = INSTRUMENT_DEFINITIONS[newInstrumentId];
-
-        const defaultRange = instDef.ranges[0].id;
-
-        // Reset tuning if applicable, or just keep as is (it won't be shown/used)
-        let newTuningId = settings.tuningId;
-        if (instDef.showTuning && INSTRUMENT_TUNINGS[newInstrumentId as 'guitar' | 'bass']) {
-            newTuningId = INSTRUMENT_TUNINGS[newInstrumentId as 'guitar' | 'bass'][0];
-        }
-
-        onUpdateSettings({
-            ...settings,
-            instrument: newInstrumentId,
-            difficulty: defaultRange as Difficulty,
-            tuningId: newTuningId
-        });
-    };
 
     const updateRhythm = (updates: Partial<RhythmSettings>) => {
         onUpdateSettings({
@@ -55,98 +30,36 @@ export const Controls: React.FC<ControlsProps> = ({ currentPitch }) => {
         });
     };
 
-    // Cast instrument to specific key if needed, or use generic record access
+    const pf = getPracticeFilter(settings);
-    const availableTunings = INSTRUMENT_TUNINGS[settings.instrument as 'guitar' | 'bass'] || [];
+    const activeFilterCount =
-    const currentInstrumentDef = INSTRUMENT_DEFINITIONS[settings.instrument];
+        (pf.keyEnabled ? 1 : 0) +
+        (pf.strings.length > 0 ? 1 : 0) +
+        (pf.fretWindowEnabled ? 1 : 0);
 
-
-
-    // Phrase Mode brings its own key/tempo machinery; the single-note
-    // key-signature select and metronome tool would be competing controls.
     const inPhraseMode = settings.gameMode === 'phrase';
 
     return (
         <div className="controls-container">
-            {/* Top Section: Settings Grid (2 Columns) */}
+            {/* Note filter: collapsed behind a button — visible only when needed */}
-            <div className="settings-grid">
+            <div style={{ display: 'flex', justifyContent: 'center', marginBottom: '8px' }}>
-                {/* Row 1, Col 1 */}
+                <button
-                <div className="control-group">
+                    className={`hint-button ${filtersOpen ? 'active' : ''}`}
-                    <label className="control-label">
+                    onClick={() => setFiltersOpen(o => !o)}
-                        <Music size={18} />
+                    title="Limit the notes used for exercises (key, strings, fret window)"
-                        <span>Instrument</span>
+                >
-                    </label>
+                    <SlidersHorizontal size={16} />
-                    <select
+                    Filter
-                        value={settings.instrument}
+                    {activeFilterCount > 0 && (
-                        onChange={handleInstrumentChange}
+                        <span style={{
-                        className="control-select"
+                            display: 'inline-block', minWidth: '18px', padding: '1px 5px',
-                    >
+                            marginLeft: '4px', borderRadius: '9px', fontSize: '11px',
-                        {Object.values(INSTRUMENT_DEFINITIONS).map(def => (
+                            background: 'var(--color-primary)', color: 'var(--color-surface)',
-                            <option key={def.id} value={def.id}>{def.displayName}</option>
+                            fontWeight: 600, textAlign: 'center'
-                        ))}
+                        }}>{activeFilterCount}</span>
-                    </select>
+                    )}
-                </div>
+                </button>
-
-                {/* Row 1, Col 2 (Conditional) */}
-                {currentInstrumentDef.showTuning ? (
-                    <div className="control-group">
-                        <label className="control-label">
-                            <Guitar size={18} />
-                            <span>Tuning</span>
-                        </label>
-                        <select
-                            value={settings.tuningId}
-                            onChange={handleTuningChange}
-                            className="control-select"
-                        >
-                            {availableTunings.map(id => (
-                                <option key={id} value={id}>{TUNINGS[id].name}</option>
-                            ))}
-                        </select>
-                    </div>
-                ) : <div />} {/* Spacer to maintain grid flow if needed, or omit to let items flow. User asked for specific rows. 
-                             If I omit, Note Set goes here. Let's omit for "Dense" feel, or keep empty div for strict rows? 
-                             The request "Top row: instrument and tuning" implies if tuning is missing, maybe just 1 item? 
-                             I'll output an empty div if I want to FORCE strict placement, but generally flow is better. 
-                             However, "Second row: note set..." suggests structure. 
-                             I will use an empty div if tuning is hidden to push Note Set to next row? 
-                             Actually, grid-template-columns: 1fr 1fr. 
-                             If Tuning is hidden, Note Set becomes Item 2. 
-                             I'll forgo complexity and just render what's available. */}
-
-                {/* Row 2, Col 2 */}
-                {!inPhraseMode && (
-                <div className="control-group">
-                    <label className="control-label">
-                        <span>Key signature</span>
-                    </label>
-                    <select
-                        value={settings.keySignature}
-                        onChange={(e) => onUpdateSettings({ ...settings, keySignature: e.target.value })}
-                        className="control-select"
-                    >
-                        <optgroup label="Major Keys">
-                            <option value="C">C Major</option>
-                            <option value="G">G Major</option>
-                            <option value="D">D Major</option>
-                            <option value="A">A Major</option>
-                            <option value="E">E Major</option>
-                            <option value="F">F Major</option>
-                            <option value="Bb">Bb Major</option>
-                            <option value="Eb">Eb Major</option>
-                        </optgroup>
-                        <optgroup label="Minor Keys">
-                            <option value="Am">A Minor</option>
-                            <option value="Em">E Minor</option>
-                            <option value="Dm">D Minor</option>
-                        </optgroup>
-                    </select>
-                </div>
-                )}
-
             </div>
-
+            {filtersOpen && <TargetNoteControls />}
-            {/* Target-note filter: unified controls, all modes */}
-            <TargetNoteControls />
 
             {/* Bottom Section: Tools Grid (2 Columns now) */}
             <div className="tools-grid" style={inPhraseMode ? { gridTemplateColumns: '1fr' } : undefined}>

src/components/PhraseTrainer.tsx

@@ -13,7 +13,7 @@ import { forwardRef, useCallback, useEffect, useImperativeHandle, useMemo, useRe
 import { useSettings } from '../context/useSettings';
 import { useAudioPlayer } from '../hooks/useAudioPlayer';
 import { usePhraseTrainer, type PhraseTrainerApi, type PhrasePhase } from '../hooks/usePhraseTrainer';
-import { getPhraseSettings, getPracticeFilter, type PhraseSettings, type PracticeFilter } from '../types/SettingsTypes';
+import { getPhraseSettings, getPracticeFilter, type PhraseSettings } from '../types/SettingsTypes';
 import { rawFrameCount } from '../hooks/rawFrameBus';
 import { audioEngine } from '../audio/AudioEngine';
 import { computePlayableNotes, isFrettedInstrument, positionsWithinWindow } from '../music/playableRange';
@@ -71,14 +71,9 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
         const setSettings = updateSettings;
         const { playNote } = useAudioPlayer();
         const phrase = getPhraseSettings(settings);
-        // Unified target-note controls: Phrase Mode reads/writes the shared
+        // Unified target-note controls: Phrase Mode reads the shared practice
-        // practice filter so all modes expose identical key/fret-window state.
+        // filter (single source of truth across all modes).
         const pf = getPracticeFilter(settings);
-        phrase.keyTonic = pf.keyTonic;
-        phrase.keyMode = pf.keyMode;
-        phrase.fretWindowEnabled = pf.fretWindowEnabled;
-        phrase.fretMin = pf.fretMin;
-        phrase.fretMax = pf.fretMax;
         // Unified metronome: phrase tempo reads from the shared rhythm BPM
         // (single source of truth across modes; the phrase-local BPM control
         // was replaced by the common metronome widget in Controls).
@@ -96,18 +91,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
             ? settings.rhythm.active && settings.rhythm.sound
             : settings.rhythm.active && settings.rhythm.sound && !settings.rhythm.syncToExercise;
         const setPhrase = useCallback((updates: Partial<PhraseSettings>) => {
-            updateSettings(s => {
+            updateSettings(s => ({ ...s, phrase: { ...getPhraseSettings(s), ...updates } }));
-                const next = { ...s, phrase: { ...getPhraseSettings(s), ...updates } };
-                // Mirror shared filter fields into the unified practice filter.
-                const shared: Partial<PracticeFilter> = {};
-                if ('keyTonic' in updates) shared.keyTonic = updates.keyTonic;
-                if ('keyMode' in updates) shared.keyMode = updates.keyMode;
-                if ('fretWindowEnabled' in updates) shared.fretWindowEnabled = updates.fretWindowEnabled;
-                if ('fretMin' in updates) shared.fretMin = updates.fretMin;
-                if ('fretMax' in updates) shared.fretMax = updates.fretMax;
-                if (Object.keys(shared).length > 0) next.practice = { ...getPracticeFilter(s), ...shared };
-                return next;
-            });
         }, [updateSettings]);
         const currentInstrumentDef = INSTRUMENT_DEFINITIONS[settings.instrument];
         const currentTuning = TUNINGS[settings.tuningId];
@@ -140,7 +124,6 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                 customMaxFret: settings.customMaxFret,
             });
         }, [pf.strings, pf.fretWindowEnabled, pf.fretMin, pf.fretMax, fretted, currentTuning,
-            phrase.fretWindowEnabled, phrase.fretMin, phrase.fretMax,
             settings.instrument, settings.difficulty, settings.tuningId, settings.customMinFret, settings.customMaxFret]);
 
         // ---- Imported score (session-only) --------------------------------------
@@ -173,8 +156,8 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
         const baseScore: Result<Score> | null = useMemo(() => {
             if (phrase.material === 'melody') {
                 const result = generateMelody({
-                    keyTonic: phrase.keyTonic,
+                    keyTonic: pf.keyTonic,
-                    keyMode: (isMode(phrase.keyMode) ? phrase.keyMode : 'major') as ModeId,
+                    keyMode: (isMode(pf.keyMode) ? pf.keyMode : 'major') as ModeId,
                     bars: phrase.bars,
                     meter: { numerator: phrase.meterNumerator, denominator: 4 },
                     rhythmLevel: phrase.rhythmLevel,
@@ -184,8 +167,8 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
             }
             if (phrase.material === 'scale') {
                 return generateScaleDrill({
-                    keyTonic: phrase.keyTonic,
+                    keyTonic: pf.keyTonic,
-                    keyMode: (isMode(phrase.keyMode) ? phrase.keyMode : 'major') as ModeId,
+                    keyMode: (isMode(pf.keyMode) ? pf.keyMode : 'major') as ModeId,
                     direction: phrase.scaleDirection,
                     coverage: phrase.scaleCoverage,
                     meter: { numerator: phrase.meterNumerator, denominator: 4 },
@@ -196,8 +179,8 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                 // 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,
+                    keyTonic: pf.keyTonic,
-                    keyMode: (isMode(phrase.keyMode) ? phrase.keyMode : 'major') as ModeId,
+                    keyMode: (isMode(pf.keyMode) ? pf.keyMode : 'major') as ModeId,
                     pattern: phrase.giulianiPattern,
                     tuningId: settings.tuningId,
                     bars: phrase.giulianiBars,
@@ -209,8 +192,8 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
             }
             if (phrase.material === 'arpeggio') {
                 return generateArpeggio({
-                    keyTonic: phrase.keyTonic,
+                    keyTonic: pf.keyTonic,
-                    keyMode: (isMode(phrase.keyMode) ? phrase.keyMode : 'major') as ModeId,
+                    keyMode: (isMode(pf.keyMode) ? pf.keyMode : 'major') as ModeId,
                     degree: (phrase.arpeggioDegree as ArpeggioDegree) || 'I',
                     pattern: phrase.arpeggioPattern,
                     coverage: phrase.arpeggioCoverage,
@@ -231,7 +214,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                 return { ok: true, value: importedScore };
             }
             return null;
-        }, [phrase.material, phrase.keyTonic, phrase.keyMode, phrase.bars, phrase.meterNumerator,
+        }, [phrase.material, pf.keyTonic, pf.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,
@@ -355,11 +338,11 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
 
         const hintPositions = useMemo(() => {
             if (!settings.showHint || !currentInstrumentDef.showTuning || !currentTuning || currentMidi === null) return [];
-            if (phrase.fretWindowEnabled) {
+            if (pf.fretWindowEnabled) {
-                return positionsWithinWindow(currentMidi, currentTuning, phrase.fretMin, phrase.fretMax);
+                return positionsWithinWindow(currentMidi, currentTuning, pf.fretMin, pf.fretMax);
             }
             return getFretboardPositions(currentMidi, currentTuning);
-        }, [settings.showHint, currentInstrumentDef, currentTuning, currentMidi, phrase.fretWindowEnabled, phrase.fretMin, phrase.fretMax]);
+        }, [settings.showHint, currentInstrumentDef, currentTuning, currentMidi, pf.fretWindowEnabled, pf.fretMin, pf.fretMax]);
 
         const handleVirtualPlay = useCallback((midi: number) => {
             if (!settings.virtualGuitarMute) {
@@ -579,11 +562,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                 </select>
                             </label>
 
-                            {(phrase.material === 'melody' || phrase.material === 'scale' || phrase.material === 'arpeggio') && (
+                            {(phrase.material === 'melody' || phrase.material === 'scale' || phrase.material === 'arpeggio') && null}
-                                <span style={{ fontSize: '11px', opacity: 0.7, alignSelf: 'center' }}>
-                                    Key/mode: use the "Target key" controls below the sheet — shared across modes.
-                                </span>
-                            )}
 
                             {phrase.material === 'melody' && (
                                 <>
@@ -799,11 +778,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                 </label>
                             )}
 
-                            {fretted && (
+                            {fretted && null}
-                                <span style={{ fontSize: '11px', opacity: 0.7, alignSelf: 'center' }}>
-                                    Fret window: use the "Fret window" controls below the sheet — shared across modes.
-                                </span>
-                            )}
 
                             {/* Pace lives in the metronome widget now:
                                 'Sync to exercise' checked = tempo pace,
@@ -816,11 +791,6 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                 />
                                 Virtual input only
                             </label>
-                            {phrase.pace === 'tempo' && (
-                                <span style={{ fontSize: '11px', opacity: 0.7, alignSelf: 'center' }}>
-                                    BPM + click: on the metronome widget below.
-                                </span>
-                            )}
                             <label className="phrase-check">
                                 <input
                                     type="checkbox"
@@ -839,7 +809,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                             </label>
                         </div>
                         {phrase.pace === 'tempo' && (
-                            <p className="phrase-note">The run clicks a full count-in bar, then one click per beat. The metronome pendulum mirrors these beats — set the tempo on the metronome tool.</p>
+                            <p className="phrase-note">Tempo and click sound live on the metronome tool (Sync checked = the run sets the pace; unchecked = play at your own pace with a free metronome).</p>
                         )}
                         <p className="phrase-note">
                             Matching checks pitch, not fingering — several fretboard positions produce the same pitch.
@@ -878,7 +848,7 @@ export const PhraseTrainer = forwardRef<PhraseHandle, PhraseTrainerProps>(
                                     onPlayNote={handleVirtualPlay}
                                     onHover={setHoveredMidi}
                                     showHints={settings.showHint}
-                                    maxFrets={Math.max(15, phrase.fretWindowEnabled ? phrase.fretMax + 1 : 0)}
+                                    maxFrets={Math.max(15, pf.fretWindowEnabled ? pf.fretMax + 1 : 0)}
                                 />
                             )
                         )}

src/components/SettingsModal.tsx

@@ -1,8 +1,32 @@
 import React, { useState } from 'react';
-import { X, Volume2, VolumeX, ChevronDown, ChevronUp, Mic, MicOff, Sun, Moon, Monitor, Clock } from 'lucide-react';
+import { X, Volume2, VolumeX, ChevronDown, ChevronUp, Mic, MicOff, Sun, Moon, Monitor, Clock, Guitar } from 'lucide-react';
 import type { AppSettings } from '../types/SettingsTypes';
 import { MIC_SENSITIVITY_DB_RANGE, MIC_DEFAULT_SENSITIVITY } from '../AppConfig';
 import type { MicrophoneDebugInfo } from '../hooks/usePitchDetector';
+import { TUNINGS, INSTRUMENT_TUNINGS } from '../music/Tunings';
+import { INSTRUMENT_DEFINITIONS } from '../music/InstrumentConfigs';
+
+/** Collapsible settings section. First section open by default. */
+const Section: React.FC<{ title: string; defaultOpen?: boolean; children: React.ReactNode }> = ({ title, defaultOpen = false, children }) => {
+    const [open, setOpen] = useState(defaultOpen);
+    return (
+        <div style={{ borderBottom: '1px solid color-mix(in srgb, var(--color-text-main) 10%, transparent)' }}>
+            <button
+                onClick={() => setOpen(o => !o)}
+                style={{
+                    width: '100%', background: 'transparent', border: 'none', color: 'inherit',
+                    display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+                    padding: '14px 0', cursor: 'pointer', font: 'inherit'
+                }}
+                aria-expanded={open}
+            >
+                <span style={{ fontSize: '15px', fontWeight: 600 }}>{title}</span>
+                {open ? <ChevronUp size={16} style={{ opacity: 0.6 }} /> : <ChevronDown size={16} style={{ opacity: 0.6 }} />}
+            </button>
+            {open && <div style={{ paddingBottom: '20px' }}>{children}</div>}
+        </div>
+    );
+};
 
 interface SettingsModalProps {
     isOpen: boolean;
@@ -78,7 +102,52 @@ export const SettingsModal: React.FC<SettingsModalProps> = ({
         <div className="help-popup-overlay" onClick={onClose}>
             <div className="help-popup" onClick={e => e.stopPropagation()}>
                 <button className="help-close" onClick={onClose}><X size={20} /></button>
-                <h2 style={{ marginTop: 0, marginBottom: '24px' }}>Settings</h2>
+                <h2 style={{ marginTop: 0, marginBottom: '12px' }}>Settings</h2>
+
+                {/* Instrument & Tuning (rarely changed — lives here now) */}
+                <Section title="Instrument" defaultOpen>
+                    <div className="control-group" style={{ marginBottom: '16px' }}>
+                        <label className="control-label" style={{ marginBottom: '8px', fontSize: '16px' }}>
+                            <Guitar size={18} />
+                            <span>Instrument</span>
+                        </label>
+                        <select
+                            value={settings.instrument}
+                            onChange={(e) => {
+                                const id = e.target.value;
+                                const def = INSTRUMENT_DEFINITIONS[id];
+                                let tuningId = settings.tuningId;
+                                if (def.showTuning && INSTRUMENT_TUNINGS[id as 'guitar' | 'bass']) {
+                                    tuningId = INSTRUMENT_TUNINGS[id as 'guitar' | 'bass'][0];
+                                }
+                                onUpdateSettings({ ...settings, instrument: id, difficulty: def.ranges[0].id, tuningId });
+                            }}
+                            className="control-select"
+                        >
+                            {Object.values(INSTRUMENT_DEFINITIONS).map(def => (
+                                <option key={def.id} value={def.id}>{def.displayName}</option>
+                            ))}
+                        </select>
+                    </div>
+                    {INSTRUMENT_DEFINITIONS[settings.instrument]?.showTuning && INSTRUMENT_TUNINGS[settings.instrument as 'guitar' | 'bass'] && (
+                        <div className="control-group">
+                            <label className="control-label" style={{ marginBottom: '8px', fontSize: '16px' }}>
+                                <span>Tuning</span>
+                            </label>
+                            <select
+                                value={settings.tuningId}
+                                onChange={(e) => onUpdateSettings({ ...settings, tuningId: e.target.value })}
+                                className="control-select"
+                            >
+                                {INSTRUMENT_TUNINGS[settings.instrument as 'guitar' | 'bass'].map(id => (
+                                    <option key={id} value={id}>{TUNINGS[id]?.name ?? id}</option>
+                                ))}
+                            </select>
+                        </div>
+                    )}
+                </Section>
+
+                <Section title="Appearance">
 
                 {/* Theme Settings */}
                 <div className="control-group" style={{ marginBottom: '24px' }}>
@@ -119,8 +188,6 @@ export const SettingsModal: React.FC<SettingsModalProps> = ({
                     </div>
                 </div>
 
-                <hr style={{ borderColor: 'rgba(255,255,255,0.1)', margin: '24px 0' }} />
-
                 {/* Animation Settings */}
                 <div className="control-group" style={{ marginBottom: '24px' }}>
                     <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', marginBottom: '8px' }}>
@@ -140,7 +207,9 @@ export const SettingsModal: React.FC<SettingsModalProps> = ({
                     </p>
                 </div>
 
-                <hr style={{ borderColor: 'rgba(255,255,255,0.1)', margin: '24px 0' }} />
+                </Section>
+
+                <Section title="Audio" defaultOpen>
 
                 <div className="control-group" style={{ marginBottom: '24px' }}>
                     <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', marginBottom: '8px' }}>
@@ -261,7 +330,9 @@ export const SettingsModal: React.FC<SettingsModalProps> = ({
                     </p>
                 </div>
 
-                <hr style={{ borderColor: 'rgba(255,255,255,0.1)', margin: '24px 0' }} />
+                </Section>
+
+                <Section title="Microphone" defaultOpen>
 
                 {/* Microphone Toggle */}
                 <div className="control-group" style={{ marginBottom: '16px' }}>
@@ -434,6 +505,8 @@ export const SettingsModal: React.FC<SettingsModalProps> = ({
                         )}
                     </div>
                 )}
+
+                </Section>
             </div>
 
         </div>

src/components/TargetNoteControls.tsx

@@ -101,6 +101,35 @@ export const TargetNoteControls: React.FC = () => {
                 )}
             </div>
 
+            {/* Display key signature (sheet notation) */}
+            <div className="control-group">
+                <label className="control-label">
+                    <span>Key signature (display)</span>
+                </label>
+                <select
+                    value={settings.keySignature}
+                    onChange={e => updateSettings(s => ({ ...s, keySignature: e.target.value }))}
+                    className="control-select"
+                    aria-label="Display key signature"
+                >
+                    <optgroup label="Major Keys">
+                        <option value="C">C Major</option>
+                        <option value="G">G Major</option>
+                        <option value="D">D Major</option>
+                        <option value="A">A Major</option>
+                        <option value="E">E Major</option>
+                        <option value="F">F Major</option>
+                        <option value="Bb">Bb Major</option>
+                        <option value="Eb">Eb Major</option>
+                    </optgroup>
+                    <optgroup label="Minor Keys">
+                        <option value="Am">A Minor</option>
+                        <option value="Em">E Minor</option>
+                        <option value="Dm">D Minor</option>
+                    </optgroup>
+                </select>
+            </div>
+
             {/* Key filter */}
             <div className="control-group">
                 <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>

src/styles/variables.css

@@ -59,24 +59,24 @@
 @media (prefers-color-scheme: dark) {
   :root {
     color-scheme: dark;
-    --color-bg: hsl(30, 20%, 10%);
+    --color-bg: hsl(220, 6%, 10%);
-    --color-surface: hsl(30, 20%, 15%);
+    --color-surface: hsl(220, 6%, 15%);
-    --color-text-main: hsl(30, 10%, 90%);
+    --color-text-main: hsl(220, 4%, 90%);
-    --color-text-muted: hsl(30, 10%, 60%);
+    --color-text-muted: hsl(220, 4%, 60%);
-    --color-primary: hsl(0, 0%, 90%);
+    --color-primary: hsl(220, 4%, 90%);
-    --color-primary-dark: hsl(0, 0%, 100%);
+    --color-primary-dark: hsl(220, 4%, 100%);
   }
 }
 
 /* Manual Dark Mode Override */
 html[data-theme="dark"] {
   color-scheme: dark;
-  --color-bg: hsl(30, 20%, 10%);
+  --color-bg: hsl(220, 6%, 10%);
-  --color-surface: hsl(30, 20%, 15%);
+  --color-surface: hsl(220, 6%, 15%);
-  --color-text-main: hsl(30, 10%, 90%);
+  --color-text-main: hsl(220, 4%, 90%);
-  --color-text-muted: hsl(30, 10%, 60%);
+  --color-text-muted: hsl(220, 4%, 60%);
-  --color-primary: hsl(0, 0%, 90%);
+  --color-primary: hsl(220, 4%, 90%);
-  --color-primary-dark: hsl(0, 0%, 100%);
+  --color-primary-dark: hsl(220, 4%, 100%);
 }
 
 /* Manual Light Mode Override */

src/types/SettingsTypes.ts

@@ -49,8 +49,6 @@ export interface PhraseSettings {
     material: PhraseMaterial;
     libraryId: string;
     /** Imported score id (the parsed score lives in component state, session-only). */
-    keyTonic: string;
-    keyMode: string; // ModeId
     bars: number; // 1–8 (melodies)
     meterNumerator: 3 | 4 | 6;
     rhythmLevel: 1 | 2 | 3;
@@ -69,10 +67,6 @@ export interface PhraseSettings {
     /** Giuliani study material (own category — voicing-enforced). */
     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;
-    fretMin: number;
-    fretMax: number;
     /** Practice range for library/import material (1-based, inclusive). */
     startBar: number;
     barCount: number;
@@ -95,8 +89,6 @@ export interface PhraseSettings {
 export const DEFAULT_PHRASE_SETTINGS: PhraseSettings = {
     material: 'melody',
     libraryId: '',
-    keyTonic: 'C',
-    keyMode: 'major',
     bars: 2,
     meterNumerator: 4,
     rhythmLevel: 1,
@@ -111,9 +103,6 @@ export const DEFAULT_PHRASE_SETTINGS: PhraseSettings = {
     arpeggioProgression: 'functional',
     giulianiPattern: 'pima',
     giulianiBars: 4,
-    fretWindowEnabled: false,
-    fretMin: 0,
-    fretMax: 4,
     startBar: 1,
     barCount: 2,
     pace: 'step',