In the late 90's, my youngest brother invited me to see Loudon Wainwright III perform at Caravan of Dreams in Fort Worth. It was a good show and Mr. Wainwright really seemed to enjoy performing that night, waggling his tongue frequently between lyric phrases as he sang. It might have been 1999 because I recall he sang Y2K.
I sat there enjoying everything about the performance, the venue and the company I was with, but wondered at that crazy tongue action. Was it a primal autoreflex triggered by deep passion for what he was doing–and really good at–engrossed in performance? Or was it just a thing he did for fun?
I dared not ask when the show came to a conclusion and Mr. Wainwright lingered on stage, apparently open to interaction with people from the audience. We had a table at the front near the stage so we rose to talk with him. Biting my own tongue to prevent saying anything about his tongue work, my brother's friend Jeff had no qualm's at all about doing so, asking pointblank: "What's with the tongue?"
That elicited a little laugh from Mr. Wainwright and a simple response: "I don't know."
So maybe it was some uncontrollable primal reflex. Very cool, if so.