#91 batch finished — all 60 famous tracks fetched + whole-mix analyzed.
First honest baseline on the full corpus (was n=5 before):
top-1 emotion hit : 22% (47% w/ overlap)
V/A quadrant hit : 42%
mean V/A error : 0.573
The center-compression hypothesis is confirmed at scale: 'playful' is the
predicted top emotion for ~18 of 60 tracks (Fleetwood, Marvin, Coltrane,
Avicii, Journey, Eminem...) because the distribution-weighted mean of the
circumplex anchors collapses toward the warm-positive centre.
Affine de-compression (gt ≈ a·pred + b, leave-one-out CV) learns exactly
that bias and corrects it:
valence: ×1.03 −0.25 (reads +0.25 too WARM — the playful pull)
arousal: ×1.70 −0.39 (compressed ~1.7x — needs the most stretch)
LOO V/A err 0.573 → 0.519, quad 42% → 50%. Modest but real & cross-validated.
calibrate.py now writes per-mode files (calibration.whole-mix.json /
calibration.stem.json) so the #92 whole-mix-vs-stem decision can compare both
without one clobbering the other; calibration.json mirrors the freshest fit.
Stem-aware batch (demucs, all 60) launched in background to settle #92 on the
full corpus, not the n=5 that PLN rightly refused to conclude on.
