Yep. Campbell gathered some of the Wrecking Crew together to record a demo for Gentle On My Mind. He would shout out direction to the others during the run through of the song. He left the rough recording for his producer to hear. The producer took the ball and ran with it. Edited out the shouted directions and released the demo as is. They were just. that. good.
Talking with Leon Russell(formerly of the wrecking crew) he talks a bit about it starting at :55.
Cool video Mick, thanks. That's what I was listening to as a kid in the early 70s. And Leon Russell is one chill dude!