I won't mention names here. A good friend of mine is touring Nashville player and I also do FOH for regional bands. Very likely it's tracks. The reason I mention the Nashville guy is.
He is currently on tour with a instantly recognizeable name in the business.
Everything is on tracks, all of it, they have a ducker built in, and when anybody wants to stop playing, they just let up on their instrument, and the track takes over.
That way they can run around, smile laugh, pose for the girls, and make generally better wrestling faces while they solo etc. When they want to go live again they just start playing their instruments with authority.
