Note2Remote

This MIDI device takes MIDI notes and drives a remote parameter with the velocity (or on/off) state of the note. Rather than toggle a parameter on/off, this device lets note turn a device on while pressed and off when released (or vice versa).

The attack and release controls allow you to smooth the on/off envelope to avoid clicks.

The velocity button lets you use the key press velocity to scale the envelope. When velocity is turned off the envelope plays full scale.

The flip buttons lets you invert the key state, such that the key not pressed well output the envelop maximum and the key pressed will output the output minimum (scaled by the velocity). In flip mode, you can use this to duck the volume of a track for example.

All other MIDI data passes through this device, so you can have several on one track or in a drum rack.

v1.5 added new modulation option in max4live so you can control params with absolute or relative change.

v1.4 not released publicly, updated code for easier maintenance with my own work.

v1.3 name change for easier searching, note learn options for easy configuration.

v1.2 fixed bug with timing errors when using low velocity values, added log/lin switch so you can choose how those crazy long fade times will impact parameters.

v1.1 allows much longer fade times.

You could totally build this yourself in a few hours if you know Max, or a few days if you are still learning. That said, it would be more productive to grab this tool and get to work making music.