Gradually un-muting ableton tracks according to live data feed.

This one is a bit hard to explain so bare with me.

I have a live data feed from COSM which is sending a value to Max.

Meanwhile I have 5 tracks in ableton, each with the separate stems of a track. Played together I have a full sounding track. Played individually I have just the vocal, bass or keys playing which sound minimal.

What I'm trying to do.

As the value of the cosm data feed increases I want the ableton tracks to gradually switch on/ unmute/ fade-up, you get the idea.

The result will be a minimal sounding track when the data feed value is low and a full sounding track when data feed is high.

I have set up some rules using 'Past' which then triggers midi outs using 'ctlout'

Does a plugin exist that makes this a little simler. Is there another way of doing this?