# Desktop ↔ Web Comparison: comm-in-thread-forum__45_sick_drummer

- **Timestamp:** 2026-06-18T15:14:09.876Z
- **Capture window:** 30000 ms

## Code
```ruby
# Source: https://in-thread.sonic-pi.net/t/sick-drummer-a-metal-drummer-bot-with-snare-fills/9372
# Author: Sunk
# Title: Sick Drummer - a metal drummer bot with snare fills
# Captured: 2026-04-24

rudiments =
 [[[1,0,1,1],[0,1,0,0]],
 [[0,1,0,0],[1,0,1,1]],
 [[1,0,1,0],[0,1,0,1]],
 [[0,1,0,1],[1,0,1,0]],
 [[1,1,0,0],[0,0,1,1]],
 [[0,0,1,1],[1,1,0,0]],
 [[0,0,0,0],[1,1,1,1]],
 [[1,1,1,1],[0,0,0,0]],
 [[1,0,0,1],[0,1,1,0]],
 [[0,1,1,0],[1,0,0,1]],
 [[1,1,1,0],[0,0,0,1]],
 [[0,0,0,1],[1,1,1,0]]]

kit =
 [[:drum_snare_hard, 0.33],
 [:drum_roll, 1.75],
 [:drum_heavy_kick, 1]]

bd_patterns =
 [[1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1],
 [1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0],
 [1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0],
 [1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0],
 [1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0],
 [1,1,1,0,1,0,1,0,1,0,1,0,1,0,1,0]]

sn_patterns =
 [[0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0],
 [0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0]]

cy_patterns =
 [[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
 [1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0],
 [1,0,1,0,0,0,1,0,0,0,1,0,0,0,1,0],
 [1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]]

len = 0.25

use_bpm 180

with_fx :gverb, room: 50, mix: 0.5 do
 with_fx :compressor, mix: 1, amp: 1 do
 with_fx :eq, high_shelf: 0.25, high: 0, mid: 0.25, low: -1.5, low_shelf: 1 do

 live_loop :fill do

 beat = 0

 bd = choose(bd_patterns)
 sn = choose(sn_patterns)
 cy = choose(cy_patterns)

 7.times do
 count = 0
 16.times do
 if bd[count] == 1
 sample :drum_heavy_kick, sustain: len
 sample :drum_heavy_kick, sustain: len * 0.0125
 end
 if sn[count] == 1
 sample :drum_snare_hard, sustain: len
 sample :drum_snare_hard, sustain: len * 0.0125
 end
 if cy[count] == 1
 sample :drum_cymbal_open, amp: 0.33, sustain: len
 end
 sleep len
 count += 1
 end
 end
 end
 end
 end
end
```

## Stats (Level 3 — observation, not inference)

| Metric | Desktop SP | SonicPi.js (web) | Δ (desk − web) |
|---------------|------------------------|-------------------------|----------------|
| Duration (s) | 31.371 | 29.696 | 1.675 |
| Peak | 1.0000 | 0.8217 | 0.1783 |
| RMS | 0.3117 | 0.2944 | 0.0173 |
| Clipping (%) | 0.23 | 0.00 | 0.23 |
| Sample rate (Hz) | 48000 | 48000 | 0 |
| Channels | 2 | 2 | — |

## Verdict
### ✅ EVENT-MATCH — per-synthdef `/s_new` onset-sequence + note parity STRUCTURE-MATCHES desktop : the engine emitted the right notes at the right times. The audio Tier-1 said _"INCONCLUSIVE — pitch-tracker method asymmetry: desktop `onset` (conf 1) vs web `contour` (conf 0.77); reconciled-contour low confidence (desktop 0.22 · web 0.77) — no Tier-1 verdict (#376)"_, but that measures stage-7+ scsynth DSP (WASM-vs-native rendering / pitch-tracker noise), not the engine. Authoritative cross-engine check passes. · ⚠ Tier-0 SOFT: level/count aggregates unreliable (Tier 1 pitch unaffected)

### Tier 0 — Validity gates
- ✓ 0.1 Sample rate consistent (48000 Hz)
- ⚠ 0.2 Capture-window misaligned (Δ 1.67s > 0.5s) — note-count / level aggregates unreliable **(SOFT — Tier 3 + 1.3 unreliable; Tier 1 pitch still valid)**
- ◦ 0.3 equal preconditions / 0.4 lossless capture / 0.5 routing sanity — not auto-checked; ensure SP.app reset + raw-float32 + FX-bus wired 

### Tier 1 — Musical correctness (THE verdict — energy/MFCC may never override)
- **1.1 Note progression:** ⚠ INCONCLUSIVE — pitch-tracker method asymmetry: desktop `onset` (conf 1) vs web `contour` (conf 0.77); reconciled-contour low confidence (desktop 0.22 · web 0.77) — no Tier-1 verdict (#376)
 - method: desktop `onset` (conf 1) · web `contour` (conf 0.77) · compared octave-invariant
 - desktop: `4,4,4,4,4,4,4,4,4,4,4,4,4,4`
 - web   : `11,11,11,10,11,11,11,11,11,11,10,11,11,10,11,11,11,11,10,11,11,11,11,11`
- **1.2 Tempo (inter-onset):** ✗ desktop 0.670s · web 0.260s/note
- **1.3 Onset count:** desktop 14 · web 120 (Δ explained by Tier-0 window misalignment)
- ◦ 1.4 note duration / 1.5 polyphony / 1.6 determinism — not auto-tracked here (unit tests cover determinism; see /)

### Tier 1.0 — Event parity (`/s_new` onset-sequence vs desktop — authoritative tiebreaker)
- **Structure (synthdef multiset):** STRUCTURE-MATCH — desktop 450 voice `/s_new`, web 446
- **Onset sequence (ε=15ms, prefix-compared, + per-tick NOTE multiset):** ✓ MATCH
 - ✓ `basic_mono_player` — 446 onsets within ε (max Δ 0ms), notes match
- ✅ **EVENT-MATCH:** structure + onset sequences both match — the engine's deterministic output (stages 1-6, terminating at the OSC emission) is correct. The audio Tier-1 divergence is stage-7+ scsynth rendering or tracker noise, not an engine bug (; #453/#379/#378 class).

### Tier 3 — Level / gain (reported; NOT a musical-correctness blocker — known ~0.5× web gain-staging)
> ⚠ Tier-0 SOFT failed — these ratios span misaligned windows; treat as indicative only.
- 3.1 RMS ratio web/desktop = 0.94× (within 0.5–2× band)
- 3.2 Peak ratio web/desktop = 0.82×
- 3.3 Clipping: desktop 0.23% · web 0% ✓ (< 1%)

### Tier 2 — Spectral / timbral (supporting only) · Tier 4 — FX/routing · Tier 5 — lifecycle
- Tier 2: see **Spectrogram comparison** section below (MFCC carries its mandatory caveat there).
- Tier 4 (FX accumulation/suppression 200ms scan, per-FX-scope energy): **not analysed** by this tool — use the FX-sweep / boundary-scan tools when FX is in scope.
- Tier 5 (Run/Stop/hot-swap, cold-start, long-run drift): **not analysed** — single capture; use `tools/test-run-stop-cycle.ts` for lifecycle.

## Source WAVs
- **Desktop:** /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/desktop-recordings/desktop_2026-06-18T15-12-52-250Z_comm-in-thread-forum__45_sick_drummer.wav
- **Web:** /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/2026-06-18T15-12-53-424Z_inline_audio.wav

## Spectrogram comparison
![spectrogram comparison](/Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/compare_2026-06-18T15-13-29-404Z_comm-in-thread-forum__45_sick_drummer_spectrogram.png)

| Metric | Value | Reading |
|---|---|---|
| L2 distance (mel-dB) | 23.67 | < 10 = very close · 10–25 = similar shape · > 25 = divergent |
| MFCC distance (timbre) | 258.08 | < 30 = similar · 30–80 = noticeably different · > 80 = unrelated |
| ↳ MFCC caveat | — | **Tier-2 supporting only.** Confounded by the known ~0.5× web gain ratio + desktop reverb-tail length; **never overrides Tier 1** . A high MFCC with a Tier-1 PITCH-MATCH means timbre/gain, not wrong notes. |
| Frames compared | 2785 | overlapping window after length-aligning |
| Peak freq desktop | 60.0 Hz | dominant frequency |
| Peak freq web | 42.0 Hz | dominant frequency |
⚠ MFCC distance 258.08 is high — **check Tier 1 first**: if pitch-track matched, this is timbre/gain (the known 0.5× + reverb tail), NOT wrong notes. Only treat as "different synth/sample chain" when Tier 1 also diverges.

## Tool stdout (debug)
### Desktop
```
▶ Desktop capture (30000ms): comm-in-thread-forum__45_sick_drummer
✓ Report: /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/desktop_2026-06-18T15-12-52-250Z_comm-in-thread-forum__45_sick_drummer.md
✓ WAV: /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/desktop-recordings/desktop_2026-06-18T15-12-52-250Z_comm-in-thread-forum__45_sick_drummer.wav
 31.37s · peak 1 · RMS 0.3117 · clip 0.23%
```
### Web
```
Launching Chromium (headed, audio capture)...
 Running: inline (30000ms)...

Capture saved: /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/inline.md
No errors detected.
```