StemLab

By Kieran Simkin · DanceFlow ecosystem · Vector logo and usage guide.

Local music analysis for stems, timing, beats, harmony, lyrics, MIDI and loopable sections for Shorts. https://kieransimkin.co.uk/

Canonical song example — Star Lights Glow (Mystery Liquid Kick)

examples/star-lights-glow-mystery-liquid-kick/ holds Bass Ben & Friends’ Star Lights Glow (Mystery Liquid Kick) as a verified 192 kbps CBR MP3 listening/analysis reference with the original supplied front-cover JPEG and ID3 metadata. The original lossless WAV remains the canonical source master, identified by SHA-256 in evidence.json rather than redistributed as a second large binary. The mix is separate from Star Lights Glow (Anthem); BPM, phase, release date and ISRC are unconfirmed. Verify with python scripts/verify_star_lights_reference.py and consult the example’s README. The MIT code licence does not license the music or artwork.

Independent beat finding and counting (experimental)

Tempo precision update: Classical autocorrelation and comb-filter lag peaks now retain their original 100 Hz integer-bin BPM while also reporting a bounded sub-frame estimate. Local tempo windows use the same refinement, and tempo families expose source-wide observed-onset-path coverage as a review diagnostic, not as calibrated confidence or automatic BPM approval. Predicted beats, observed onset candidates and inferred ordinal gaps remain distinct. See beat-evidence documentation.

stemlab compare-beats now compares model-free audio, N-dimensional DanceRudiments recordings, rig captures and verified motion-package accents. Five complementary classical rhythm decoders produce reviewable BPM, beat count, phase, accent-cycle and local-tempo hypotheses. It can also import existing Beat This!/BeatNet/Beat Transformer/All-In-One model result JSON without re-running models; no model weights are downloaded. Cross-source phase scores require explicit clock offsets. No inferred downbeat or predicted grid is silently accepted as a real detection or canonical timeline. See usage and evidence schema and the model and implementation research roadmap.

The review now groups half/double tempo families rather than majority-voting correlated algorithms, scores DP coverage across the original source, and fits original saved model timestamps with robust residual/drift guards. Optional --annotation NAME=FILE evaluates beat timing only against a matching, human-reviewed, SHA-bound annotation; separately-held-out reliability calibration