Music

The Music page turns a description into a finished piece of music: "tense military sci-fi combat loop, driving percussion, low brass stabs, 120 bpm", "calm exploration ambience, warm pads, sparse piano, no drums", "victory fanfare, bright horns, timpani roll". Tracks can be auditioned, downloaded, and saved to Saved Content, where the Sound agent can trim, fade and loop them.

1. 1Pick a model. Both are Stable Audio 3; they differ in quality ceiling and maximum length (see below).
2. 2Describe the music. Name the genre, the instruments, the mood and the tempo.
3. 3Set the length with the slider, or use a preset — 15s sting, 30s loop, 1 min bed, 2 min, 4 min.
4. 4Optionally open advanced for a negative prompt, a seed, or prompt expansion.
5. 5Generate, then audition it in the player. Generation typically takes a few seconds.
6. 6Download the file, or Save Music to add it to Saved Content — as a new item or a new version of an existing track.

A flat credit price per generation, taken from the model you chose and shown on the page before you generate. It is derived from what the generation costs Tonetta, so the number you are quoted is the number you are charged. Credits are reserved before generation and refunded automatically if it fails, so a failed generation never costs anything.

This is deliberately unlike sound effects, which are priced per second. The music upstream bills per clip, so pricing it per second would have made long tracks expensive for no extra cost.

Every track you save is handed to the Sound agent as it lands. It levels the track to -20 LUFS with a -3 dBTP ceiling — the room a music bed needs under everything else — trims only true silence (a quiet intro or a long tail is the music, not padding), cleans the edges and delivers 48 kHz 16-bit stereo WAV. That export becomes the item's next active version; the version you saved stays underneath it. A track named or described as a loop is left untouched at its seams.

Pass gameReady: false on the save (or saveGameReady on the MCP tool) to keep a track exactly as generated. The pass is a Sound turn and is billed like one.

Game music usually has to loop seamlessly, and a generated track ends when it ends. Save the track, open it from Saved Content, and use Post-process with the Sound agent: it can find a loop point, crossfade the seam, trim the tail and match the loudness to the rest of your mix. Each step you keep becomes a new version of the same track, and the original stays.

Generating a longer take and asking the Sound agent to cut a loop out of the middle often works better than asking for a short loop directly — and since length is free, it costs the same.

You can also start with the agent rather than the form: Talk to the Sound agent takes a brief, generates with the same Stable Audio 3 models (a paid call it proposes with its price unless you asked for the track), compares takes, shapes the one you choose to the scene, and exports it game-ready. By API: POST /api/v1/sound/sessions with a message and contentType: "music", or the start_sound_session MCP tool.

Saved tracks live in Saved Content under the Music filter, with the generation prompt as their description and the decoded duration. Saving supports Save as New and Update Existing; updating appends a version and makes it active.

Music generation requires the music:write scope, and the catalog music:read. The API uploads the result to storage and returns a URL (not base64); pass save to also store it in Saved Content.

curl -s https://<host>/api/v1/music/generate \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Tense military sci-fi combat loop, driving percussion, low brass stabs, dark synth pulse, 120 bpm",
    "durationSeconds": 90,
    "negativePrompt": "vocals",
    "save": { "name": "Combat Loop A", "tags": ["combat", "loop"] }
  }'

{
  "success": true,
  "result": {
    "audioUrl": "https://<r2-public>/music/<org>/unassigned/<uuid>.mp3",
    "audioKey": "music/<org>/unassigned/<uuid>.mp3",
    "contentType": "audio/mpeg",
    "filename": "music_<uuid>.mp3",
    "model": "music-sa3-medium",
    "seed": 16425460,
    "request": { "prompt": "Tense military sci-fi...", "durationSeconds": 90 },
    "tokensCharged": 8,
    "savedContent": { "id": "...", "name": "Combat Loop A", "contentType": "music", ... }
  }
}