Generation 0 · parent mix
The Sun on the Solstice
181.2 seconds. Prompted as bright C-major folk-pop, but measured as a sustained Gmaj7#11 center with an average friction coefficient of 0.26.
Live paid run · June 10, 2026
The Chiral Double
THIRI measured the friction between a generated vocal stem and its instrumental stem. MusicAPI.ai then covered the isolated vocal into a darker mirror arrangement, testing how far accompaniment can move while the melody stays fixed.
THIRI + MusicAPI.ai
What was tested
The third run tested stem-aware reharmonization: split a generated song into vocals and accompaniment, extract MIDI from both layers, measure their interval friction over time, then ask MusicAPI.ai to rebuild a new accompaniment under the same vocal line.
The parent song, The Sun on the Solstice , was prompted as bright C-major folk-pop. The measured result settled into a single repeating Gmaj7#11 color. THIRI-derived chiral tags requested a distant dark progression: Dbmaj7#11 | Bbm9 | G#dim | C7#9 .
The cover did change the arrangement style, but the vocal melody held the harmony close to home. The generated double measured D | Dsus4 | Gmaj7#11 | A13 with nearly the same average friction as the parent, proving that the vocal stem acts as a strong key-center anchor.
105
credits traced
2
generation passes
0.26
parent avg friction
11
public assets
Playable outputs
Audio assets
The public audio set includes the parent mix, parent stems, the chiral cover mix, and the selected chiral instrumental stem used for verification.
Generation 1 · chiral cover
The Solstice Shadow
124.5 seconds. The vocal-stem cover shifted the arrangement toward darker trip-hop texture while measuring D, Dsus4, Gmaj7#11, and A13.
Generated imagery
Visual assets
Two image files ship with the run: a text-free generated artwork source and the final 3000 x 3000 album cover treatment.
Symbolic layer
MIDI, ledger, and metadata
The dual-stem MIDI pass made the friction audit possible: vocals supplied melody pitch classes, instrumentals supplied chord templates, and each paid API call was bracketed with credit snapshots.
The ledger totals 105 credits: create_music, two stems/basic calls, three MIDI calls, and one cover_music call, each costing 15 credits.