mcp_opendaw_create_harmony_line
Generates a consonant harmony line from a melody by shifting notes by diatonic scale steps in a given key, ideal for vocal harmonies and counter-melodies.
Instructions
Create a harmony line from an existing melody using diatonic intervals.
Reads notes from a source melody and creates a parallel harmony line at a specified diatonic interval. The harmony stays in key — each note is shifted by N scale steps (not semitones), producing consonant harmony automatically.
Harmony intervals (diatonic):
third: +2 scale steps — the most common harmony (Lennon-McCartney, Everly Brothers, country duets). Sweet and consonant.
sixth: +5 scale steps — wider, jazzier. Creates open, airy harmony.
fifth: +4 scale steps — power harmony, medieval/organum sound.
fourth: +3 scale steps — suspended, ambiguous. Gregorian/modal.
octave: +7 scale steps (or -7) — doubling, not true harmony but useful for layering.
Essential for: vocal harmonies, string pads behind melody, guitar harmonies, counter-melody foundation, thickening lead lines.
source_unit/track/region: Location of the source melody. target_unit/track/region: Where to write the harmony. -1 = create new track/region automatically. interval: third, sixth, fifth, fourth, octave. root_note + scale: The key for diatonic interval calculation. The harmony notes are guaranteed to be in this scale. direction: "above" or "below" — place harmony above or below the melody. velocity_scale: Multiply source velocities by this (default 0.8 = harmony slightly quieter than melody).
Returns the created harmony notes.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| scale | No | major | |
| interval | No | third | |
| direction | No | below | |
| root_note | No | C | |
| source_unit | No | ||
| target_unit | No | ||
| source_track | No | ||
| target_track | No | ||
| source_region | No | ||
| target_region | No | ||
| velocity_scale | No |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |