Yes! I remember Gibson singing that Kumbaya thing at Newport in 64. He introduced Joan Baez and sang with her and wow, what a time that was.
If anyone ever asked (or asks) me to join hands and sing Kumbaya , I'd tell them to go away, I need my hands to play my guitar. Besides, I hate touchy-feely folk music. I'll leave that to Dr. Phil. And John Denver.