Can't be done with a GM compat MIDI synth solution, because all Percussion sounds are on only one MIDI channel, typically ch 10, in some few cases these days, ch 16.

Since the Volume command, cc7, is "by the channel" then changing the Vol also changes all instruments on that channel.

There are some MIDI synths that allow for assigning Percussion sounds to different channels, but there is a much easier way to do this.

First Render each track, one at a time to an Audio track, by Soloing that specific track each time.

Then Mute the MIDI tracks and use the Audio Mixer or the new Automated Nodes to set the volume for each sound.

Mix as Audio and not MIDI.


--Mac