diff --git a/src/App.jsx b/src/App.jsx
index 87d7ea8..5df8590 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -8,6 +8,7 @@ import Tuner from './components/Tuner'
 import Piano from './components/Piano'
 import Settings from './components/Settings'
 import DebugView from './components/DebugView'
+import DrumView from './components/DrumView'
 import { NOTES, detectKey, detectTopKeys, matchChordFromChroma, detectRepeatingProgression, getChordTones, getChordCandidates, getNoteHistoryAnalysis } from './lib/theory'
 import settingIcon from './assets/setting-icon.png'
 
@@ -49,7 +50,8 @@ export default function App() {
   // ── Instrument view + tuner ───────────────────────────────────────────────────
   const [instrument, setInstrument] = useState('piano')  // 'piano' | 'guitar' | 'bass'
   const [showTuner, setShowTuner]   = useState(false)
-  const [showDebug, setShowDebug]   = useState(false)
+  const [showDebug, setShowDebug]       = useState(false)
+  const [showDrumView, setShowDrumView] = useState(false)
   const [monoColor, setMonoColor]   = useState(() => loadStored('wtf_monoColor', false))
 
   // ── Mic permission error ──────────────────────────────────────────────────────
@@ -63,9 +65,11 @@ export default function App() {
 
   // ── Stable refs for values used inside callbacks ──────────────────────────────
   const showDebugRef    = useRef(showDebug)
+  const showDrumViewRef = useRef(showDrumView)
   const lockedKeyRef    = useRef(null)
   const listenStartRef  = useRef(null)
   useEffect(() => { showDebugRef.current = showDebug }, [showDebug])
+  useEffect(() => { showDrumViewRef.current = showDrumView }, [showDrumView])
   useEffect(() => { localStorage.setItem('wtf_monoColor', JSON.stringify(monoColor)) }, [monoColor])
   useEffect(() => { if (isListening) listenStartRef.current = Date.now() }, [isListening])
 
@@ -184,9 +188,11 @@ export default function App() {
     effectiveKeyRef.current = keyInfo
   }
 
-  // ── Waveform handler: feeds oscilloscope in debug view ───────────────────────
+  // ── Waveform handler: feeds oscilloscope / drum view ─────────────────────────
   const handleWaveform = useCallback((data) => {
-    if (showDebugRef.current) setDebugWaveform(data)
+    if (showDebugRef.current || showDrumViewRef.current) {
+      setDebugWaveform({ ...data, onsets: [...onsetTimestampsRef.current] })
+    }
   }, [])
 
   // ── Note handler: drives key detection (pitch-based) ──────────────────────────
@@ -569,6 +575,22 @@ export default function App() {
         )}
       </div>
 
+      {/* ── Rhythm / drum analyser — collapsible ── */}
+      <div className="mb-3 bg-panel border border-border rounded-xl overflow-hidden">
+        <button
+          onClick={() => setShowDrumView(v => !v)}
+          className="w-full flex items-center justify-between px-4 py-2 text-sm text-gray-400 hover:text-gray-200 transition-all"
+        >
+          <span>RHYTHM ANALYSER</span>
+          <span>{showDrumView ? '▲' : '▼'}</span>
+        </button>
+        {showDrumView && (
+          <div className="border-t border-border p-4">
+            <DrumView waveform={debugWaveform} bpm={bpm} />
+          </div>
+        )}
+      </div>
+
       {/* ── Tuner — collapsible ── */}
       <div className="bg-panel border border-border rounded-xl overflow-hidden">
         <button
diff --git a/src/components/DrumView.jsx b/src/components/DrumView.jsx
new file mode 100644
index 0000000..eeaedd4
--- /dev/null
+++ b/src/components/DrumView.jsx
@@ -0,0 +1,181 @@
+import { useRef, useEffect } from 'react'
+
+// Map a frequency (Hz) to a bin index in the 256-bin log spectrum (40–4000 Hz)
+function freqToBin(freq) {
+  return Math.round(255 * Math.log(freq / 40) / Math.log(4000 / 40))
+}
+
+function bandMax(spectrum, lo, hi) {
+  if (!spectrum) return 0
+  const a = freqToBin(lo)
+  const b = Math.min(freqToBin(hi), spectrum.length - 1)
+  let max = 0
+  for (let i = a; i <= b; i++) if (spectrum[i] > max) max = spectrum[i]
+  return max
+}
+
+const BANDS = [
+  { label: 'Kick',     lo: 40,   hi: 120,  color: '#ef4444' },
+  { label: 'Snare',    lo: 120,  hi: 300,  color: '#f59e0b' },
+  { label: 'Mid',      lo: 300,  hi: 1000, color: '#22c55e' },
+  { label: 'Presence', lo: 1000, hi: 4000, color: '#60a5fa' },
+]
+
+const TIMELINE_MS = 4000   // onset timeline window
+const RMS_HISTORY = 180    // ~3s at 60fps
+
+export default function DrumView({ waveform, bpm }) {
+  const rmsHistRef    = useRef([])
+  const beatCanvasRef = useRef(null)
+  const rmsCanvasRef  = useRef(null)
+
+  const spectrum = waveform?.spectrum ?? null
+  const bandLevels = BANDS.map(b => bandMax(spectrum, b.lo, b.hi))
+
+  // Accumulate RMS history
+  useEffect(() => {
+    if (waveform == null) return
+    const h = rmsHistRef.current
+    h.push(Math.min(waveform.rms * 10, 1))
+    if (h.length > RMS_HISTORY) h.shift()
+  }, [waveform])
+
+  // Draw onset / beat timeline
+  useEffect(() => {
+    const canvas = beatCanvasRef.current
+    if (!canvas) return
+    const ctx = canvas.getContext('2d')
+    const W = canvas.width, H = canvas.height
+
+    ctx.fillStyle = '#0a0a0a'
+    ctx.fillRect(0, 0, W, H)
+
+    const onsets = waveform?.onsets ?? []
+    const now = performance.now()
+
+    // Beat grid aligned to the most recent onset
+    if (bpm) {
+      const beatMs = 60000 / bpm
+      const numBeats = Math.ceil(TIMELINE_MS / beatMs) + 1
+      const latest = onsets[onsets.length - 1]
+      const phase = latest != null ? (now - latest) % beatMs : 0
+      for (let b = 0; b <= numBeats; b++) {
+        const ageMs = b * beatMs - phase
+        if (ageMs < 0 || ageMs > TIMELINE_MS) continue
+        const x = W * (1 - ageMs / TIMELINE_MS)
+        ctx.strokeStyle = 'rgba(255,255,255,0.07)'
+        ctx.lineWidth = 1
+        ctx.beginPath(); ctx.moveTo(x, 0); ctx.lineTo(x, H); ctx.stroke()
+      }
+    }
+
+    // Onset dots + vertical tails
+    const recent = onsets.filter(t => now - t <= TIMELINE_MS)
+    for (const t of recent) {
+      const age = now - t
+      const x = W * (1 - age / TIMELINE_MS)
+      const alpha = Math.pow(1 - age / TIMELINE_MS, 0.4)
+      ctx.strokeStyle = `rgba(168,85,247,${(alpha * 0.35).toFixed(2)})`
+      ctx.lineWidth = 1
+      ctx.beginPath(); ctx.moveTo(x, 0); ctx.lineTo(x, H); ctx.stroke()
+      ctx.fillStyle = `rgba(168,85,247,${alpha.toFixed(2)})`
+      ctx.beginPath(); ctx.arc(x, H / 2, 5, 0, Math.PI * 2); ctx.fill()
+    }
+
+    // "Now" edge
+    ctx.strokeStyle = 'rgba(255,255,255,0.18)'
+    ctx.lineWidth = 2
+    ctx.beginPath(); ctx.moveTo(W - 1, 0); ctx.lineTo(W - 1, H); ctx.stroke()
+  }, [waveform, bpm])
+
+  // Draw RMS envelope
+  useEffect(() => {
+    const canvas = rmsCanvasRef.current
+    if (!canvas) return
+    const ctx = canvas.getContext('2d')
+    const W = canvas.width, H = canvas.height
+    const h = rmsHistRef.current
+
+    ctx.fillStyle = '#0a0a0a'
+    ctx.fillRect(0, 0, W, H)
+    if (h.length < 2) return
+
+    const barW = W / RMS_HISTORY
+    for (let i = 0; i < h.length; i++) {
+      const x = W * (i / RMS_HISTORY)
+      const barH = h[i] * H
+      const v = Math.round(h[i] * 160 + 60)
+      ctx.fillStyle = `rgb(${v},30,${v})`
+      ctx.fillRect(x, H - barH, Math.max(barW - 0.5, 1), barH)
+    }
+  }, [waveform])
+
+  const noData = !waveform
+
+  return (
+    <div className="space-y-5">
+
+      {/* Band meters */}
+      <div>
+        <p className="text-xs text-gray-600 font-mono uppercase tracking-widest mb-2">Frequency Bands</p>
+        <div className="flex gap-3" style={{ height: 96 }}>
+          {BANDS.map((b, i) => (
+            <div key={b.label} className="flex flex-col items-center gap-1 flex-1">
+              <div className="flex-1 w-full bg-gray-900 rounded-sm relative overflow-hidden">
+                {noData ? (
+                  <div className="absolute inset-0 flex items-center justify-center">
+                    <span className="text-[9px] text-gray-700 font-mono">—</span>
+                  </div>
+                ) : (
+                  <div
+                    className="absolute bottom-0 left-0 right-0 rounded-sm"
+                    style={{
+                      height: `${bandLevels[i] * 100}%`,
+                      backgroundColor: b.color,
+                      transition: 'height 60ms linear',
+                    }}
+                  />
+                )}
+              </div>
+              <span className="text-[10px] font-mono text-gray-500 uppercase">{b.label}</span>
+            </div>
+          ))}
+        </div>
+      </div>
+
+      {/* Onset timeline */}
+      <div>
+        <p className="text-xs text-gray-600 font-mono uppercase tracking-widest mb-2">
+          Onset Timeline{bpm ? ` · ${bpm} BPM` : ''}
+          <span className="ml-2 text-gray-700 normal-case">← 4 seconds</span>
+        </p>
+        <canvas
+          ref={beatCanvasRef}
+          width={800}
+          height={56}
+          className="w-full rounded"
+          style={{ height: 56 }}
+        />
+        {noData && (
+          <p className="text-xs text-gray-700 font-mono mt-1 text-center">Start listening to see hits</p>
+        )}
+      </div>
+
+      {/* Volume envelope */}
+      <div>
+        <p className="text-xs text-gray-600 font-mono uppercase tracking-widest mb-2">
+          Volume Envelope
+          <span className="ml-2 text-gray-700 normal-case">← ~3 seconds</span>
+        </p>
+        <canvas
+          ref={rmsCanvasRef}
+          width={800}
+          height={56}
+          className="w-full rounded"
+          style={{ height: 56 }}
+        />
+      </div>
+
+    </div>
+  )
+}