Kirk Byron Jones in his book, The Jazz of Preaching, tells this story about Mr. marsalis

"Wynton Marsalis was playing, "I Don’t Stand a Ghost of a Chance With You," unaccompanied. At the most dramatic point of his conclusion, someone’s cell phone went off." David Hajdu was present and tells what happened next… "

"Marsalis paused for a beat, motionless, and his eybrows arched. I scrawled on a sheet of notepaper, MAGIC, RUINED. The cell-phone offender scooted into the hall as the chatter in the room grew louder. Still frozen at the microphone, Marsalis replayed the silly cell-phone melody note for note. Then he repeated it, and began improvising variations on the tune. The audience slowly came back to him. In a few minutes he resolved the improvisation–which had changed keys once or twice and throttled down to a ballad tempo–and ended up exactly where he had left off: "with…you…" The ovation was tremendous."

Improvisation–an essential skill for any jazz theologian.