I saw Phil Keaggy in concert last Friday. The guy is an amazing acoustic guitarist. He can play incredible riff after incredible riff and each part sounds logical and very musical.
Snopes says
this story is untrue or at least not proven. But after seeing him play, you could see how such a story could get started.
The other thing he did, which I had never seen done live, is that he would play a riff and loop it -- then add layers on top of that. He got some very intricate stuff going on this way.
He's also got a very listenable high-tenor voice. Considering that he's in his late 50s, I was amazed at how good a range he still has.