MIDI, KAR, and instrumental jobs.

Lyra’s MIDI flow searches a fixed set of instrumental queries and shows only metadata candidates that pass the title, arrangement, duration, and contradiction rules. Choosing a candidate downloads it into private temporary storage, checks its identity, size, and duration on the device, and only then starts transcription.

The processing path

1. The selected source is downloaded into a private job directory and checked against the selected video ID, source hash, a 20 MB compressed-input ceiling, and a four-minute duration ceiling. Android decodes to bounded mono PCM before inference; longer decoded recordings are rejected rather than trimmed. Local conversion requires Android until other platforms provide bounded decoding. The model loads only when conversion starts.
2. Basic Pitch reads the local source through a loopback URL, avoiding a Dart-to-browser base64 copy, then transcribes it directly to MIDI while preserving performance timing.
3. Discovery remains strict about arrangement evidence and contradictory vocal or dense-accompaniment claims, but no audio-classification model is bundled.
4. Lyra validates the MIDI by reading it back and renders the generated notes for preview.
5. The source hash stays bound to the job until the source is promoted to the library.

Sources outside the local memory limits are rejected and no MIDI or library entry is created. The app never removes vocals, trims an intro, or falls back to a dense mix to force a result.

Choosing MIDI or KAR

MIDI is created first. Use Lyric Studio to synchronize lyrics to that selected arrangement, then export KAR. Lyrics found for the original recording are suggestions only and are never treated as trusted timing for a new arrangement.