# Desktop ↔ Web Comparison: comm-in-thread-forum__46_lofi_hip_hop

- **Timestamp:** 2026-06-18T15:15:35.656Z
- **Capture window:** 30000 ms

## Code
```ruby
# Source: https://in-thread.sonic-pi.net/t/lofi-hip-hop-creation/9432
# Author: boda
# Title: Lofi hip hop creation
# Captured: 2026-04-24

# lo-fi
use_bpm 60

chords =
 [
 (chord_degree :iv, :C4, :major),
 (chord_degree :iii, :C4, :major),
 (chord_degree :ii, :C4, :major),
 chord(:C4, :major7),
 chord(:C4, :major7),
 ]

live_loop :chord do
 use_synth :piano
 play chords.tick, decay: 2
 sleep 2
 play chords.tick, decay: 2
 sleep 2
 play chords.tick, decay: 2
 sleep 2
 play chords.tick, decay: 1
 sleep 1
 play chords.tick, decay: 1
 sleep 1
end

with_fx :distortion do
 with_fx :lpf do

 live_loop :bass do
 use_synth :subpulse
 play chords.tick[-1], decay: 2, amp: 0.1
 sleep 2
 play chords.tick[-1], decay: 2, amp: 0.1
 sleep 2
 play chords.tick[-1], decay: 2, amp: 0.1
 sleep 2
 play chords.tick[-1], decay: 1, amp: 0.1
 sleep 1
 play chords.tick[-1], decay: 1, amp: 0.1
 sleep 1
 end
 end
end

hats = [1,0,1,0] * 4
live_loop :hats do
 sample :hat_bdu if hats.tick == 1
 sleep 0.25
end

tom = [1,0,0,0,0,0,1,0,0,0,0,1,0,0,1,0]
live_loop :clap do
 sample :tabla_ghe1, amp: 0.5 if tom.tick == 1
 sleep 0.5 / 2
end

pattern = [1,0,1,1]
live_loop :test do
 sample :perc_snap2, amp: 0.5 if pattern.tick == 1
 sleep 1
end

with_fx :bitcrusher do
 live_loop :melody do
 use_synth :kalimba
 use_random_seed 4
 for _ in 1..8 do
 play chord(:F, :major7), amp: 5
 sleep [0.25, 0.25, 0.5, 1].choose
 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 | 0.3908 | 0.2359 | 0.1549 |
| RMS | 0.0525 | 0.0312 | 0.0213 |
| Clipping (%) | 0.00 | 0.00 | 0.00 |
| 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 _"PITCH DIVERGENCE at pc 1 (desktop 9 vs web 5)"_, 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:** ✗ PITCH DIVERGENCE at pc 1 (desktop 9 vs web 5)
 - method: desktop `contour` (conf 0.91) · web `contour` (conf 0.92) · compared octave-invariant
 - desktop: `5,9,5,9,4,9,5,4,7,7,7,7,7,7,5,5,4,11,4,4,5,5,9,5`
 - web   : `5,5,9,4,9,4,7,7,5,7,2,7,7,2,7,5,11,5,4,4,11,4,4,11`
- **1.2 Tempo (inter-onset):** ✗ desktop 0.280s · web 0.230s/note
- **1.3 Onset count:** desktop 79 · web 82 (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 454 voice `/s_new`, web 447
- **Onset sequence (ε=15ms, prefix-compared, + per-tick NOTE multiset):** ✓ MATCH
 - ✓ `kalimba` — 236 onsets within ε (max Δ 5ms), notes match
 - ✓ `basic_mono_player` — 93 onsets within ε (max Δ 0ms), notes match
 - ✓ `piano` — 76 onsets within ε (max Δ 0ms), notes match
 - ✓ `basic_stereo_player` — 23 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 = 0.59× (within 0.5–2× band)
- 3.2 Peak ratio web/desktop = 0.60×
- 3.3 Clipping: desktop 0% · 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_2026-06-18T15-14-19-287Z_comm-in-thread-forum__46_lofi_hip_hop.wav
- **Web:** /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/2026-06-18T15-14-20-505Z_inline_audio.wav

## Spectrogram comparison
![spectrogram comparison](/Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/compare_2026-06-18T15-14-56-438Z_comm-in-thread-forum__46_lofi_hip_hop_spectrogram.png)

| Metric | Value | Reading |
|---|---|---|
| L2 distance (mel-dB) | 14.82 | < 10 = very close · 10–25 = similar shape · > 25 = divergent |
| MFCC distance (timbre) | 130.60 | < 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 | 331.0 Hz | dominant frequency |
| Peak freq web | 350.8 Hz | dominant frequency |
⚠ MFCC distance 130.60 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__46_lofi_hip_hop
✓ Report: /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/desktop_2026-06-18T15-14-19-287Z_comm-in-thread-forum__46_lofi_hip_hop.md
✓ WAV: /Users/mrityunjaybhardwaj/Documents/projects/sonicPiWeb/.captures/desktop-recordings/desktop_2026-06-18T15-14-19-287Z_comm-in-thread-forum__46_lofi_hip_hop.wav
 31.37s · peak 0.3908 · RMS 0.0525 · clip 0%
```
### Web
```
Launching Chromium (headed, audio capture)...
 Running: inline (30000ms)...

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