mcp_opendaw_apply_velocity_curve
Apply a deterministic velocity curve (ramp, arc, trough, or power) across MIDI notes to shape dynamics for crescendos, build-ups, and expressive phrasing.
Instructions
Apply a velocity envelope across notes — ramp, arc, trough, or custom power curve.
Maps each note's position within its region to a velocity value via a mathematical curve. Unlike humanize_notes (random variation), this applies a deterministic envelope shape — useful for build-ups, fade-ins, crescendo rolls, and expressive phrasing.
unit_index: AU index. track_index: Note track index. region_index: Region index (-1 = all regions on the track). curve_type: Curve shape:
"ramp_up" — linear increase from start_velocity to end_velocity
"ramp_down" — linear decrease from start_velocity to end_velocity
"arc" — rises to end_velocity then falls back to start_velocity (peak in middle)
"trough" — falls to start_velocity then rises to end_velocity (dip in middle)
"power" — exponential curve controlled by 'power' param (>1 = fast rise, <1 = slow rise) start_velocity: Velocity at curve start 0-1 (default 0.3). end_velocity: Velocity at curve end 0-1 (default 1.0). power: Exponent for "power" curve type (default 1.0 = linear). 2.0 = sharp attack, 0.5 = slow swell.
Returns per-region note counts and total notes shaped.
Examples: apply_velocity_curve(curve_type="ramp_up", start_velocity=0.2, end_velocity=1.0) # build-up apply_velocity_curve(curve_type="arc", start_velocity=0.4, end_velocity=0.95) # expressive phrase apply_velocity_curve(curve_type="power", power=2.0, start_velocity=0.1, end_velocity=1.0) # sharp attack
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| power | No | ||
| curve_type | No | ramp_up | |
| unit_index | No | ||
| track_index | No | ||
| end_velocity | No | ||
| region_index | No | ||
| start_velocity | No |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |