02 / MESSAGES

OSC messages and their results

Live performance messages

Address	Arguments	Blender result
`/companion/note`	track, node ID, synth name, parameter/value pairs	Creates or replaces a live voice. The dashboard and automatic track visual update.
`/companion/set`	track, node ID, parameter/value pairs	Updates that voice. `gate 0` removes it.
`/companion/free`	track, node ID	Removes the voice.
`/companion/choke`	track	Removes active type 2 and 3 voices on the track.
`/rack/control`	name, normalized value	Stores a value clamped to 0–1 and applies mappings whose track is `control_name`.
`/rack/reset`, `/companion/reset`, `/transport/reset`	none	Clears queued events, voices, controls, cue values, and live performance state.
any other address	zero or more values	Creates or updates `osc:/address` on the Rack OSC Score Empty. Numeric first arguments can also feed a live mapping whose track matches the address.

Performance examples

/companion/note bass 12 sine freq 55 amp 0.4 gate 1
/companion/set bass 12 freq 82.41
/companion/set bass 12 gate 0
/rack/control scene_energy 0.75
/transport/reset

OSC score JSON

Each exported event contains seconds, address, args, and kind. Events must be sorted, occur at or after zero, and occur before durationSeconds.

{
  "format": "rack-osc-score",
  "version": 1,
  "durationSeconds": 10,
  "events": [
    {"seconds": 0, "address": "/visual/kick", "args": [1], "kind": "event"},
    {"seconds": 0.08, "address": "/visual/kick", "args": [0], "kind": "curve"}
  ]
}

Kind	Use	Import behavior
`event`	A discrete hit or manually placed cue.	Bakes the value and adds a timeline marker.
`state`	A value intended to remain active until it changes.	Bakes the value and adds a timeline marker.
`curve`	Dense automation or sampled values.	Bakes numeric values without adding timeline markers.

The importer treats the argument shape separately from the kind: no arguments become a counter; one number becomes a numeric F-Curve; strings and multiple arguments are restored from embedded score data while scrubbing.

Import and bake →