Hey guys!
I’m trying to map a physical midi controller fader to control a mixer groups volume, how would I go about doing this? I can’t seem to get the right script or OSC in the midi mapping to get it to work.
Thanks heaps 
Hey @Adam_Molinaro,
What you need is a Custom Script to scale the incoming CC value and forward it as OSC.
Here’s how to set it up:
1. Make sure your mixer group is set up in Live
The track or group in Ableton needs the +G:GROUPNAME flag, e.g. +G:DRUMS. The OSC path will then be /mixer/drums/volume (lowercase, underscores for spaces — e.g. +G:MONITOR MIX → /mixer/monitor_mix/volume).
2. Create the MIDI mapping
Go to Settings → MIDI Mapping, OSC & Scripting → Edit MIDI Mapping, then:
- Click the + button to add a new mapping (turn your fader/knob)
- Set the channel and CC number that your controller sends
- Set the CC Value column to “Any Value” — this is the key part: it makes the script fire on every incoming CC value. If you leave it on a specific value (like “Value 126”), it will only trigger at that exact value.
- Set the Action to Custom Script.
3. Paste this script
// Incoming CC value comes through midi.value (0–127)
// Scale to 0.0–0.85 so the top of the fader lands at 0 dB
const scaled = (midi.value / 127) * 0.85;
// Send it to your mixer group
sendOsc("/mixer/drums/volume", scaled);
Replace drums with your group’s lowercase name. If you’d rather let the fader go above 0 dB (up to Ableton’s +6 dB ceiling), drop the * 0.85 and just use midi.value / 127.
Would that work for your use case?