Goal: I'd like to find single pre-made user tracks for an upright bass, rhythm guitar, and drums and use this for all the songs I play on the piano with by lead guitar friend. It's like trying to have the same trio backing us all the time.

Is there such a "thing"?

Is there such a process that can produce this?

Hopefully my question makes some sense......or not

Thanks in advance!!!

Bud

Yes, you can find and save as a style then it will use the same tracks.
You can only have a "single track" with combined tracks without drums as you can't transpose them.
Some more here also https://www.realband.org/usertracks.html