mcp_opendaw_add_chord_tension
Add tension notes like 9th, 11th, or 13th to existing chords for jazz harmony. Extend triads into complex chords without manual pitch calculation.
Instructions
Add a tension/extension note to an existing chord — jazz harmony.
Adds an extension note (9th, 11th, 13th, or alterations) to a chord already on the timeline. This is how triads become jazz chords — stack a 9th on a C major triad and it becomes Cmaj9, add a b13 to a G7 and it becomes G7b13. The extension is calculated from the chord root, so you don't need to know the exact pitch.
extension: The tension note to add:
"9" — major 9th (2 semitones above root, +14 from root). Adds color and warmth. C → D. The most common jazz extension.
"b9" — minor 9th (1 semitone above root, +13). Dark, tense. Dominant chords in minor keys, flamenco, film scores. C → Db.
"#9" — augmented 9th (3 semitones, +15). The Hendrix chord sound. Bluesy, gritty. C → D#.
"11" — perfect 11th (5 semitones above root, +17). Suspended, open. C → F. Can clash with 3rd — use carefully.
"#11" — augmented 11th (6 semitones, +18). Lydian sound. Dreamy, floating. C → F#. Common in modal jazz.
"13" — major 13th (9 semitones above root, +21). Full, rich. The ultimate jazz extension. C → A. Adds completeness.
"b13" — minor 13th (8 semitones, +20). Dark, dramatic. Minor key dominants. C → Ab. Spanish/orchestral feel.
chord_position: Beat position of the chord (finds root = lowest note). octave: Which octave to place the extension in (3-7, default 5). Higher = more color, lower = more grounded. velocity: Velocity of the added note (0-1, default 0.6 = subtle).
Returns root pitch, extension pitch, extension name, chord size.
Example:
Add 9th to first chord — Cmaj → Cmaj9
add_chord_tension(0, 2, 0, 0.0, extension="9")
Add b13 for dark dominant — G7 → G7b13
add_chord_tension(0, 2, 0, 4.0, extension="b13")
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| octave | No | ||
| velocity | No | ||
| extension | No | 9 | |
| unit_index | Yes | ||
| track_index | Yes | ||
| region_index | Yes | ||
| chord_position | Yes |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |