`rig.music.pattern`

v0.31.0 · draft 7 fields 1 required

Fields

Field	Type		Meaning
`steps`	array<rig.music.step>	required	Ordered `rig.music.step` cells; length = pattern length
`rootNote`	integer0 – 127	optional	Optional. MIDI pitch 0-127 (scale root); absent = 60
`scale`	enumchromatic · major · minor · dorian · pentatonic	optional	Optional. chromatic, major, minor, dorian, pentatonic; absent = chromatic
`lane`	int	optional	Optional. Voice index when several patterns play together
`stepsPerBeat`	number> 0	optional	Optional. Steps advanced per transport beat; absent = 4 (16th notes)
`loopStartStep`	int	optional	Optional. First step of the loop region; absent = 0
`loopEndStep`	int	optional	Optional. Step after the last looped step; absent = `steps.length` (loop the whole pattern)

Ordered steps. Format when present.

Compose rig.meta.named for the label. Tempo comes from transport - no bpm here.

A rig.music.sequencer has a pattern. A pattern has steps.

No parallel numSteps - use steps.length.

stepsPerBeat is musical time: the wall-clock rate comes from transport bpm. A tracker that used an absolute per-pattern speed converts through the transport - pick bpm and stepsPerBeat so the step rate matches the original (default stepsPerBeat 4 is sixteenth notes at the transport tempo).

steps is a single row. A drum grid is several pattern entities sharing one rig.music.sequencer, each with its own lane - not one pattern holding a matrix. Lanes advance together, so patterns in one stack should be the same length; a host running unequal lengths is polymetric, which the Contract does not describe.

Omit lane for a single-voice pattern. Two patterns in one stack sharing a lane number is a document error, not a layering instruction.

JSON Schema

Resolves at https://rig.works/schemas/rig.music.pattern.schema.json — raw file.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://rig.works/schemas/rig.music.pattern.schema.json",
  "title": "rig.music.pattern",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "steps": {
      "type": "array",
      "items": {
        "$ref": "./rig.music.step.schema.json"
      }
    },
    "rootNote": {
      "type": "integer",
      "minimum": 0,
      "maximum": 127
    },
    "scale": {
      "type": "string",
      "enum": [
        "chromatic",
        "major",
        "minor",
        "dorian",
        "pentatonic"
      ]
    },
    "lane": {
      "$ref": "./_defs.schema.json#/$defs/int"
    },
    "stepsPerBeat": {
      "type": "number",
      "exclusiveMinimum": 0
    },
    "loopStartStep": {
      "$ref": "./_defs.schema.json#/$defs/int"
    },
    "loopEndStep": {
      "$ref": "./_defs.schema.json#/$defs/int"
    }
  },
  "required": [
    "steps"
  ]
}