diff --git a/src/App.tsx b/src/App.tsx
index 4d82286..d9a5b6a 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -59,14 +59,20 @@ function App() {
     // Find range config
     const rangeConfig = currentInstrumentDef.ranges.find(r => r.id === settings.difficulty);
 
+    const getNotesFromConfig = (config: typeof rangeConfig) => {
+      if (!config) return [];
+      if (config.notes) return config.notes;
+      return Array.from({ length: config.max - config.min + 1 }, (_, i) => config.min + i);
+    };
+
     if (rangeConfig) {
-      return Array.from({ length: rangeConfig.max - rangeConfig.min + 1 }, (_, i) => rangeConfig.min + i);
+      return getNotesFromConfig(rangeConfig);
     }
 
     // Fallback if difficulty ID doesn't match current instrument (e.g. after switch)
     // Return first range of current instrument
     const fallbackRange = currentInstrumentDef.ranges[0];
-    return Array.from({ length: fallbackRange.max - fallbackRange.min + 1 }, (_, i) => fallbackRange.min + i);
+    return getNotesFromConfig(fallbackRange);
 
   }, [settings.difficulty, currentInstrumentDef]);
 
diff --git a/src/components/Controls.tsx b/src/components/Controls.tsx
index edb523b..5b9ddcf 100644
--- a/src/components/Controls.tsx
+++ b/src/components/Controls.tsx
@@ -2,7 +2,7 @@ import { Settings, Guitar, Music, Gauge } from 'lucide-react';
 import { TUNINGS, INSTRUMENT_TUNINGS } from '../music/Tunings';
 import { INSTRUMENT_DEFINITIONS } from '../music/InstrumentConfigs';
 
-export type Difficulty = 'all' | 'first_pos' | 'open' | 'e_string';
+export type Difficulty = string;
 
 export interface RhythmSettings {
     mode: 'bpm' | 'seconds';
@@ -112,7 +112,7 @@ export const Controls: React.FC<ControlsProps> = ({ settings, onUpdateSettings }
             <div className="control-group">
                 <label className="control-label">
                     <Settings size={18} />
-                    <span>Range</span>
+                    <span>Note Set</span>
                 </label>
                 <select
                     value={settings.difficulty}
diff --git a/src/music/InstrumentConfigs.ts b/src/music/InstrumentConfigs.ts
index cde54a1..c73d987 100644
--- a/src/music/InstrumentConfigs.ts
+++ b/src/music/InstrumentConfigs.ts
@@ -2,11 +2,12 @@ import type { Instrument } from './Tunings';
 
 export type ClefMode = 'treble' | 'bass' | 'grand';
 
-export interface RangeConfig {
+export interface NoteSetConfig {
     id: string;
     label: string;
     min: number; // MIDI number
     max: number; // MIDI number
+    notes?: number[]; // Explicit list of notes (overrides min/max for generation if present)
 }
 
 export interface InstrumentDefinition {
@@ -14,7 +15,7 @@ export interface InstrumentDefinition {
     displayName: string;
     clefMode: ClefMode;
     transpose: number; // Semitones to add to MIDI to get written note (e.g. +12 for guitar)
-    ranges: RangeConfig[];
+    ranges: NoteSetConfig[];
     showTuning: boolean;
 }
 
@@ -26,8 +27,19 @@ export const INSTRUMENT_DEFINITIONS: Record<string, InstrumentDefinition> = {
         transpose: 12, // Guitar sounds octave lower than written, so we add 12 to played midi to show it
         showTuning: true,
         ranges: [
-            { id: 'open', label: 'Open Strings', min: 40, max: 64 }, // Dynamic logic handled in App for specific strings, but this is fallback
-            { id: 'first_pos', label: 'First Position', min: 40, max: 44 + 12 }, // Approx
+            {
+                id: 'open',
+                label: 'Open Strings',
+                min: 40,
+                max: 64,
+                notes: [40, 45, 50, 55, 59, 64] // E2, A2, D3, G3, B3, E4
+            },
+            {
+                id: 'first_pos',
+                label: 'First Position',
+                min: 40,
+                max: 68 // E2 to G#4 (First 4 frets on high E string e(64) -> g#(68))
+            },
             { id: 'all', label: 'All Notes', min: 40, max: 76 }
         ]
     },