I don’t have a particular link handy, but if you search YouTube for “Phil Keaggy Salvation Army Band Wheaton”, you’ll find various recordings of his song, Salvation Army Band, performed live at Wheaton College. It’s phenomenal. You could also search for his recorded track, “The Further Adventures Of...”, which is just an entirely improvisational session with only himself and a drummer. It is really incredible.
By the way, “The Further Adventures Of...” is over 12 minutes long, so give it some time, as it starts slow and builds to awesomeness by the middle to end of the track.