---
log: 021
title: "The editor knew all along"
date: 2026-08-13
task: "#148 album cuts wrong (also #149, #150, #151)"
tags: [mastering, tooling, opal2026, boundaries, salvage]
shareable: true
---

## Cap (what & why)

PLN uploaded the OPAL-26 album privately to SoundCloud to test it, and heard the
problem in about ten seconds: *"cuts are wrong! WAP starts on the last sound of
prev, then silence, then first WAP sound at 00:07? the next track, something
about drums, starts on a wap sound??"*

He asked for the bug chased "down to its bottom source and throughout erroneous
layers". There were four.

## Manœuvre (how)

Checked the arithmetic before the audio. Every one of the fifteen track
durations in the shipped segments file equalled a gig-log tab-switch delta to
within 0.01 s — so the boundaries had never touched the audio at all. Then
measured the log-to-audio anchor honestly, by correlating three fader CC curves
against their own stems.

Then built the detectors: silence, per-orbit activity, and eventually tempo.
Then built the thing that was actually missing, a verifier.

## Prise (findings / artifacts)

- **The gig log's `track` event is a TAB-FOCUS event, not a music event.** PLN
  opens the next track's file while the current one is still playing, reads it,
  edits it, evaluates it seconds later. The editor knows when he LOOKED at a
  track; only the audio knows when it STARTED. Lag measured **+1.0 s to +50.7 s,
  always the same direction**.
- The anchor was 1.1 s off as well. True offset 745 s, measured three ways, all
  agreeing.
- **The layer that hid it:** the provenance note claimed the boundaries were
  "aligned to audio by cross-correlation, r>=0.99, 20 probes, 0.00 ms spread".
  Every word true — of a *different* measurement. That r>=0.99 was the
  take-to-master audio alignment. It never validated the log-to-audio anchor.
- **Silence is the weakest evidence.** Shipping "a real gap is authoritative"
  put four boundaries 15-47 s early, because a livecoded track is full of holes
  and a breakdown inside the outgoing track outvoted the orbit evidence.
- **Tempo was the lens that worked**, and PLN asked for it as a third detector
  once he saw it. Not by estimating tempo — that is unstable at exactly the
  transition you care about, and a 128 BPM track read 171.4 for long stretches —
  but by scoring the onset flux against both KNOWN BPMs from the setlist and
  finding the crossover. It caught a handover that gap and orbit-flip both
  missed by 47 seconds.
- Verifier scores: shipped boundaries **3/15**, refined **12/15**.
- Along the way, two taste complaints where the obvious metric said he was
  wrong: "the kick doesn't hit" (level said +1.3 dB ABOVE median; PUNCH said
  buried) and "the bass is saturated" (nothing is clipped; everything that was
  masking it left).

## Sel (the shareable learning)

**My first verifier passed the two tracks PLN had complained about.** I wrote it
specifically to catch his bug, ran it, got a satisfying 3/15 failure report, and
only noticed on a second read that WAP and Drums were both in the passing
column. A verifier that passes the case you built it for is not yet a verifier —
it is a hypothesis wearing a lab coat.

And the bigger one, which he put better than I did: *"tbh why dont we have
events when i ctrl+enter a track? the hud changes, we could know when one is in
focus no?"*

We spent an afternoon reconstructing from audio something the editor knew
exactly, at the millisecond, and threw away. Every clever detector in this log is
compensation for a missing log line. The instrument that measures best is the
one standing closest to the event.

## Hameçon (hook)

*"Four detectors, three afternoons, and a verifier that agreed with the bug —
to recover a fact the text editor had known all along and never bothered to
write down."*
