# Real recordings and modifications

GuitarSet1.1.0, Qingyang Xi and colleagues, https://doi.org/10.5281/zenodo.3371780, CC BY4.0: archived00_BN1-129-Eb_solo microphone human guitar with per-string JAMS note labels. Original hash/provenance retained. New declared crop15–20s reuses the old performance, not a new performer.

Vienna4x22 Piano Corpus, Werner Goebl, https://doi.org/10.21939/4X22, CC BY4.0: archived human Mozart_K331_1st-mov_p01 grand-piano recording and hardware key MIDI. New declared crops36–41s and61–66s reuse the old performance. Fixed audio-minus-MIDI offset-0.63375s inherited from prior source calibration, not fitted to these outputs. Key duration is not pedal/acoustic decay.

Modifications2026-11-15: declared5s crops; arithmetic stereo-to-mono average, common0.5gain, half-second zero tail, controlled AAC128kbps or ALAC encoding intoM4A with the existing local FFmpeg, and local PCM16 WAV decode. These are controlled exported human-recording copies, not authentic iPhone Voice Memo exports; mobile/Safari and real phone microphone behavior are untested. No source-author endorsement; no synthesized instrument replacement. Carried-in notes are separately retained rather than scored as new attacks.