mcp_opendaw_create_passacaglia
Create a passacaglia by defining a repeating bass ostinato and evolving chord harmonies above it, with control over rhythm, variation style, and arrangement parameters.
Instructions
Create a passacaglia — repeating bass ostinato with evolving harmonies above.
A foundational Baroque form (Bach BWV 582, Buxtehude) adapted to modern contexts (film scoring, metal, electronic). A short bass pattern (4-8 notes) repeats throughout while chords or arpeggiations evolve above it, creating cumulative tension. Distinct from ostinato (single repeating pattern), pedal_point (single sustained note), and bordun (drone chord).
bass_pattern: Space-separated MIDI pitches for the bass ostinato (e.g. "36 43 41 36" = C2 G2 F2 C2). Default is a classic descending bass. bass_rhythm: Space-separated durations in beats matching bass_pattern (e.g. "1 1 1 1" = quarter notes, "0.5 0.5 1 2" = syncopated). bass_repeats: How many times the bass pattern repeats (1-16, default 4). chord_pattern: Comma-separated chord names for the upper voices (e.g. "Cm,Ab,Eb,Bb"). Supports: maj, min, m7, maj7, dom7, sus2, sus4, dim, aug. If fewer chords than repeats, chords cycle. chord_octave: Octave for chord notes (1-8, default 4). variation_style: How upper harmonies are voiced — "block" (sustained chords), "arpeggiated" (broken chord pattern), "melodic" (stepwise counter-melody). beats_per_bar: Time signature beats (3/4=3, 4/4=4, 6/8=6, default 4). bass_velocity: Velocity of bass notes (0-1, default 0.75). chord_velocity: Velocity of chord/variation notes (0-1, default 0.55). unit_index: AU index with note track (-1 = find first AU with note tracks). track_index: Note track index within the AU. start_beat: Position in beats where the passacaglia begins.
Returns notes created, bass pattern length, total bars, variation style.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| start_beat | No | ||
| unit_index | No | ||
| bass_rhythm | No | 1 1 1 1 | |
| track_index | No | ||
| bass_pattern | No | 36 43 41 36 | |
| bass_repeats | No | ||
| chord_octave | No | ||
| bass_velocity | No | ||
| beats_per_bar | No | ||
| chord_pattern | No | Cm,Ab,Eb,Bb | |
| chord_velocity | No | ||
| variation_style | No | block |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |