armada: collab stem kit for Mafia + PunkAChien from Montreuil26, CosmicFest is stemless

armada/tasks/2026-10-06-collab-stem-kit-mafia-punkachien.md

+---
+log: 2026-10-06
+title: "The siren that wasn't there: a real stem kit from Montreuil"
+date: 2026-10-06
+task: n/a
+tags: [collab, stems, salvage, backups]
+shareable: true
+---
+
+## Cap (what & why)
+Send a friend the stems of PunkAChien and the track after it, as played at CosmicFest 2026.
+
+## Manœuvre (how)
+CosmicFest 2026-08-22 turned out to be stemless: Zoom stage mic only (`ZOOM0067.MP3`).
+No Ardour take on XPS22 between Take99 (08-14) and Take100 (08-29). Its only stems are
+demucs splits, and those mangle the dub siren. PunkAChien -> Mafia Sans Serif was also played
+at Montreuil26 (Take89, 2026-05-22), in reverse order (Mafia -> PunkAChien), and there the
+per-orbit stems were already cut on the user-confirmed boundaries (`Montreuil26_master/tracks_bandcamp/stems/`).
+Copied those, cut matching reference slices from `Montreuil26_streaming_final.flac`, and checked
+alignment by cross-correlating onsets: lag 0 ms over a +/-2 s window, for both tracks.
+
+## Prise (findings / artifacts)
+- `~/Work/Sound/Prod/Kits/ParVagues_Montreuil26_Mafia-PunkAChien_stems.zip` (272 MB, 15 stems +
+  2 reference mixes + README). Stems are 48k/16-bit, as is the source export.
+- Measured tempo: Mafia 160.0 BPM; PunkAChien ~170 (autocorr. ambiguous between 85 and 170).
+- "Aria Sans Serif" in the Montreuil stem dirs is the old name: renamed Mafia Sans Serif in the kit.
+- Backups: Take103-109 (Sept 24-28) exist only on XPS24; Take89 and older only on LGD;
+  Take91-102 on XPS22 + LGD (count+size match, not hashed). Seagate not mounted.
+
+## Sel (the shareable learning)
+- An AI split is a lens, not a source: it can't give back a siren the mic smeared. The same
+  pair played elsewhere, recorded per orbit, beats the "right" gig rendered by demucs.
+- `track_recording_map.json` stops at 2026-06-05: the "2-second answer" took 30 minutes.
+
+## Hameçon (hook)
+"The gig we wanted had no stems. The gig we had did."

armada/tide-table/performance_notes.md

@@ -821,3 +821,12 @@ video (`REC-20260928-215506-screen.mp4`; the master sits at +3.80 s in it).
   critical); the right edge is midiviz's border.
 - Lesson for long takes: 10 min on one track is hard to sustain; a planned
   two-track arc (rose_rouge -> sept1) is the natural shape.
+
+## 2026-10-06 — CosmicFest 2026 demucs stems, and Montreuil26 as the collab source
+- On the CosmicFest demucs split (stemless gig, Zoom only): **"like the dubsiren gosh
+  the siren ahahah"** — the AI separation visibly mangles the dub siren.
+  Demucs stems are not shippable for collab.
+- **"i played both similarly-ish iirc at Montreuil26"** — PunkAChien and Mafia Sans
+  Serif, Take89 (2026-05-22), so Montreuil26 is the stem source for that pair.
+- Naming: **"indeed the real name now is Mafia"** — "Aria Sans Serif" (Montreuil26
+  stem dirs) is the old name.