---
log: 010
title: "The ear caught what the math missed"
date: 2026-06-05
task: "#19 PunkAChien · #26 resplit · #27 Hamburg stems · metadata provenance"
tags: [mastering, boundaries, calibration, provenance, tooling, stem-map]
shareable: true
---

## Cap (what & why)
Master PunkAChien properly (stem-vs-stem A/B), apply validated boundaries to re-split
the Montreuil set, and keep mastering honest — separate from metadata.

## Manœuvre (how)
Built a stem-map validation instrument (orbit-presence over time + audio player + ±5s
boundary-stepping). PLN validated cuts by ear; his timestamps disagreed with my computed
ones — which exposed a **time-base bug**: I'd assumed stem = master + 75 (a HEAD_TRIM).
The new `tidal-ears master locate` tool settled it by cross-correlation (known split sits
at proxy 2309.1s, z=29): stem ≈ master − 3. Re-windowed PunkAChien, recovered Hamburg
stems from Take87 via the same `locate`, re-split all 15 Montreuil tracks.

## Prise (findings / artifacts)
- New reusable tools: `tidal-ears master {eda, stemmap, locate}`; `build_master.py`,
  `resplit_montreuil.py`; `stemmap.html`, `judge.html`. Ledger: `boundaries_take89_
  validated.json`; ear-archive: `performance_notes.md`. 15 tracks → `Prod/Montreuil26_resplit/`.
- Both PunkAChien takes stem-mastered. `meth_bass` plays zero seconds; cpluck is the riff.

## Sel (the shareable learning)
- **The performer's ear is a debugger.** Two casual "I hear Piment at 6:00" comments
  surfaced a 75-second systematic offset that loudness math had hidden. Build the tool that
  lets the artist validate by ear, and it audits your pipeline for free.
- **Distrust derived time-bases; verify by content.** A cross-correlation `locate` against a
  known-good clip beats any HEAD_TRIM arithmetic.
- **Mastering ≠ metadata.** A hallucinated venue ("La Cour des Lézards" vs real **Les
  Nouveaux Sauvages**) taught: store facts with provenance (`type:locator` + `as_of`), pull
  gig metadata from the canonical site source, never invent — never store self-notes in data.

## Hameçon (hook)
"My own ear caught a 75-second bug in my mastering pipeline before any meter did — by
noticing a sample came in 'a little early'."

## Sillage (what it unlocks)
A trustworthy boundary loop (validate-by-ear → export → re-split), a fair stem-vs-stem
A/B for the lead single, and an edge-detection heuristic to build next.
