After systematic testing, the bpm field in musicGenerationConfig does not affect the generated audio’s tempo in lyria-realtime-exp.
Test setup: Raw WebSocket connection. Automated sequence alternating between bpm: 60 and bpm: 200 every 5 seconds, with PAUSE → config → RESET_CONTEXT → PLAY between each switch. Prompt: "house, simple beat".
Result: Zero audible difference between 60 and 200 BPM. The model generates at a self-determined fixed tempo regardless of the value sent. No error or acknowledgment is returned from the server after config changes.
Also tested: Double-nested format {"musicGenerationConfig": {"musicGenerationConfig": {"bpm": 200}}} — causes WS close with code 1007. Single camelCase {"musicGenerationConfig": {"bpm": 200}} — accepted silently, no effect.
Density and brightness work correctly mid-stream.
Expected: Tempo changes to reflect the BPM value sent, as documented.