Music-task fine-tuning, not exposure, induces chroma equivalence

Grasse & Tata test whether chroma equivalence (the circular, octave-periodic component of pitch, the Shepard/Drobisch helix, distinct from linear pitch height) emerges in trained audio networks via representational similarity analysis on NSynth notes [grasse-tata-2026-chroma-equivalence-anns] All self-supervised pretrained models (Wav2Vec 2.0, Data2Vec, others) show significant pitch-height encoding but none show significant chroma equivalence, including after self-supervised fine-tuning on a speech+music mixture [grasse-tata-2026-chroma-equivalence-anns] Mere exposure to music in the training data is therefore not sufficient to induce chroma equivalence [grasse-tata-2026-chroma-equivalence-anns] Supervised fine-tuning on polyphonic piano-note transcription (MAESTRO) does induce significant chroma equivalence in both base models, while fine-tuning on speech recognition (a control) does not [grasse-tata-2026-chroma-equivalence-anns] A hard-coded constant-Q transform baseline trivially exhibits chroma equivalence, serving as a positive control for the RSA methodology; no causal intervention is performed [grasse-tata-2026-chroma-equivalence-anns] Exact Spearman coefficients live only in bar-chart figures not recoverable from the text, so the entry rests on the pre-registered-model RSA and Bonferroni-corrected significance testing [grasse-tata-2026-chroma-equivalence-anns]