Keyboardia

Describe what is happening musically in a session — rhythm, pitch content, inferred key, and chords — without changing anything. Use this to explain music rather than to edit it. Results come from the same music-theory module the browser's Key Assistant and Chromatic Grid use, and report where the analysis is uncertain instead of guessing.

Create a new editable Keyboardia session with the normal defaults and return its shareable URL. The session starts with no tracks; use edit_session to add them. Pass the same idempotency_key when retrying so an uncertain attempt cannot leave duplicate sessions behind.

Make one narrow, retry-safe edit to an existing collaborative session. After every attempt, the next Keyboardia call must be get_session for the same session. A successful call includes a backwards-compatible compact snapshot plus an acknowledgement. That snapshot is not authoritative verification; do not make another edit or finish from it. Read with get_session next. Supported operations: add_track, set_track_instrument, set_track_pan, set_steps, and set_tempo. set_steps changes only the named steps; it never replaces a track or session. set_track_instrument replaces only a track's sound source, keeping its pattern, mix, timing, and custom name.

Export the session as a base64-encoded Standard MIDI File, matching what Keyboardia's own Export MIDI produces for the same music. The session is not modified. The result lists any session features a MIDI file cannot carry rather than approximating them silently.

Read the current tempo and compact track patterns from an existing Keyboardia session.

Freeze the current music into a new immutable session and return its URL. The source session stays editable at its own URL. Only call this when someone explicitly asks to publish; it is never a side effect of editing or exporting.

Copy an existing session — published or editable — into a new editable session that records the original as its source. The source is never modified, so this is how to continue from published work.