add piano view with instrument toggle

src/App.jsx

@@ -7,6 +7,7 @@ import SafeNotes from './components/SafeNotes'
 import Fretboard from './components/Fretboard'
 import ProgressionSuggestions from './components/ProgressionSuggestions'
 import Tuner from './components/Tuner'
+import Piano from './components/Piano'
 import { NOTES, detectKey, detectTopKeys, matchChordFromChroma, detectRepeatingProgression } from './lib/theory'
 
 // Key detection tuning
@@ -22,6 +23,9 @@ export default function App() {
   // ── Listening state ──────────────────────────────────────────────────────
   const [isListening, setIsListening] = useState(false)
 
+  // ── Instrument view ───────────────────────────────────────────────────────
+  const [instrument, setInstrument] = useState('guitar')  // 'guitar' | 'piano'
+
   // ── Key: auto-detected + optional lock ───────────────────────────────────
   const [keyInfo, setKeyInfo]     = useState(null)     // auto-detected
   const [lockedKey, setLockedKey] = useState(null)     // { root, mode } or null
@@ -182,6 +186,21 @@ export default function App() {
 
       {/* ── Controls bar ── */}
       <div className="mb-4 flex flex-wrap gap-3 items-center p-3 bg-panel border border-border rounded-xl">
+        {/* Instrument toggle */}
+        <div className="flex bg-surface border border-border rounded-full p-0.5 text-sm">
+          {['guitar', 'piano'].map(v => (
+            <button
+              key={v}
+              onClick={() => setInstrument(v)}
+              className={`px-4 py-1 rounded-full capitalize transition-all ${
+                instrument === v ? 'bg-accent text-white' : 'text-gray-400 hover:text-gray-200'
+              }`}
+            >
+              {v}
+            </button>
+          ))}
+        </div>
+
         {/* Key lock */}
         {lockedKey ? (
           <div className="flex items-center gap-2">
@@ -256,11 +275,15 @@ export default function App() {
         <SafeNotes keyInfo={effectiveKey} currentChord={currentChord} />
         <ProgressionSuggestions keyInfo={effectiveKey} />
         <div className="md:col-span-2">
-          <Fretboard
+          {instrument === 'guitar' ? (
-            keyInfo={effectiveKey}
+            <Fretboard
-            currentChord={currentChord}
+              keyInfo={effectiveKey}
-            pentatonicOnly={false}
+              currentChord={currentChord}
-          />
+              pentatonicOnly={false}
+            />
+          ) : (
+            <Piano keyInfo={effectiveKey} currentChord={currentChord} />
+          )}
         </div>
         <div className="md:col-span-2">
           <Tuner />

src/components/Piano.jsx

@@ -0,0 +1,133 @@
+import { getFullScale, getChordTones, NOTES } from '../lib/theory'
+
+// White keys in order within an octave, mapped to pitch class
+const WHITE_KEYS = [
+  { pc: 0, label: 'C' },
+  { pc: 2, label: 'D' },
+  { pc: 4, label: 'E' },
+  { pc: 5, label: 'F' },
+  { pc: 7, label: 'G' },
+  { pc: 9, label: 'A' },
+  { pc: 11, label: 'B' },
+]
+
+// Black keys: position (in white-key units from left of octave) and pitch class
+const BLACK_KEYS = [
+  { pc: 1,  offset: 0.7 },  // C#
+  { pc: 3,  offset: 1.7 },  // D#
+  { pc: 6,  offset: 3.7 },  // F#
+  { pc: 8,  offset: 4.7 },  // G#
+  { pc: 10, offset: 5.7 },  // A#
+]
+
+const OCTAVES    = 2          // number of octaves shown
+const KEY_W      = 40         // white key width
+const KEY_H      = 130        // white key height
+const BLACK_W    = 26         // black key width
+const BLACK_H    = 82         // black key height
+const LABEL_Y    = KEY_H - 10 // y of note label on white key
+const BLACK_LABEL_Y = BLACK_H - 8
+
+function keyColor(isChordTone, isScale, isBlack) {
+  if (isChordTone) return { fill: '#f59e0b', text: '#000' }
+  if (isScale)     return { fill: '#a855f7', text: '#fff' }
+  return isBlack
+    ? { fill: '#1f1f1f', text: '#6b7280' }
+    : { fill: '#f5f5f5', text: '#6b7280' }
+}
+
+export default function Piano({ keyInfo, currentChord }) {
+  const { root, mode } = keyInfo ?? {}
+  if (!root) return null
+
+  const scaleSet = new Set(getFullScale(root, mode).map(n => NOTES.indexOf(n)))
+  const chordSet = currentChord
+    ? new Set(getChordTones(currentChord).map(n => NOTES.indexOf(n)))
+    : new Set()
+
+  const totalWhite = WHITE_KEYS.length * OCTAVES
+  const svgW = totalWhite * KEY_W + 2
+  const svgH = KEY_H + 20  // +20 for octave labels
+
+  return (
+    <div className="bg-panel border border-border rounded-2xl p-6">
+      <p className="text-sm text-gray-500 uppercase tracking-widest mb-4">
+        Piano — {root} {mode}
+        {currentChord && <span className="text-amber-400 ml-2">/ {currentChord}</span>}
+      </p>
+
+      <div className="overflow-x-auto">
+        <svg width={svgW} height={svgH} style={{ display: 'block', minWidth: svgW }}>
+
+          {/* White keys */}
+          {Array.from({ length: OCTAVES }, (_, oct) =>
+            WHITE_KEYS.map((k, wi) => {
+              const x = (oct * WHITE_KEYS.length + wi) * KEY_W + 1
+              const isChordTone = chordSet.has(k.pc)
+              const isScale     = scaleSet.has(k.pc)
+              const { fill, text } = keyColor(isChordTone, isScale, false)
+              return (
+                <g key={`w-${oct}-${wi}`}>
+                  <rect
+                    x={x} y={0}
+                    width={KEY_W - 1} height={KEY_H}
+                    fill={fill}
+                    rx={3}
+                    stroke="#2a2a2a"
+                    strokeWidth={1}
+                  />
+                  <text
+                    x={x + KEY_W / 2} y={LABEL_Y}
+                    textAnchor="middle"
+                    fontSize={9}
+                    fontWeight="600"
+                    fill={text}
+                  >
+                    {k.label}{oct + 3}
+                  </text>
+                </g>
+              )
+            })
+          )}
+
+          {/* Black keys (drawn on top) */}
+          {Array.from({ length: OCTAVES }, (_, oct) =>
+            BLACK_KEYS.map((k, bi) => {
+              const x = (oct * WHITE_KEYS.length + k.offset) * KEY_W + 1
+              const isChordTone = chordSet.has(k.pc)
+              const isScale     = scaleSet.has(k.pc)
+              const { fill, text } = keyColor(isChordTone, isScale, true)
+              return (
+                <g key={`b-${oct}-${bi}`}>
+                  <rect
+                    x={x} y={0}
+                    width={BLACK_W} height={BLACK_H}
+                    fill={fill}
+                    rx={2}
+                    stroke="#111"
+                    strokeWidth={1}
+                  />
+                  <text
+                    x={x + BLACK_W / 2} y={BLACK_LABEL_Y}
+                    textAnchor="middle"
+                    fontSize={8}
+                    fontWeight="600"
+                    fill={text}
+                  >
+                    {NOTES[k.pc]}
+                  </text>
+                </g>
+              )
+            })
+          )}
+
+        </svg>
+      </div>
+
+      <div className="mt-3 flex gap-5 text-xs text-gray-500">
+        <span><span className="text-amber-400">●</span> Chord tone</span>
+        <span><span className="text-accent">●</span> Scale note</span>
+      </div>
+    </div>
+  )
+}