Make a music track with ElevenLabs Music: a song, a score, a background bed. Either describe the whole track in prompt (genre, mood, instruments, tempo, era, how it builds) or pass a plan you got from plan_music, edited however you like. seconds sets the length, 3 to 600 (default 30). For music under a video pass project_id (or video_seconds): the track is asked at the video's length, and if it comes back shorter the answer says how to loop it on a musical boundary; tell the creator and never leave the end silent. One take per ask: a second track minutes after the first needs another_take_reason with the creator's own words. instrumental true keeps every voice out. HOUSE RULE: only put music on a job when the customer actually asked for music; never add a bed because it feels empty, and when music is asked for keep it to what they named. This tool is NOT for sound effects: whooshes, impacts, chimes, risers, foley and ambiences are generate_sound_effect. Billed per 10 seconds (a token quote applies) and the file is saved to your library. Returns audio_url, duration_seconds and generation_id.