So I would be dancing around and doing my scat, singing along what they were doing. And just watching those guys go into another world, with their sounds, you know, and the expressions of their faces changed and their behavior was different... something comes over them, some kind of extraordinary force comes over them... moves them, you know, strange feeling, or maybe just a huge kind of epiphany, suddenly, skies open up and you can see eternity.

— Roswell Rudd, qtd. in Larry Fink’s Somewhere There’s Music

Viz Fink, see also this and this: