Cavale is the criminal in the story. She kidnaps Slim and holes him up in her lair. The two of them love and spar, and create a language of their own, improvising poetry. When we got to the part where we had to improvise an argument in a poetic language, I got cold feet. “I can’t do this,” I said. “I don’t know what to say.”

“Say anything,” he said. “You can’t make a mistake when you improvise.”

“What if I mess it up? What if I screw up the rhythm?”

“You can’t,” he said. “It’s like drumming. If you miss a beat, you create another.”

In this simple exchange, Sam taught me the secret of improvisation, one that I have accessed my whole life.

Cowboy Mouth opened at the end of April at the American Place Theatre on West Forty-sixth Street. In the play, Cavale tries to recreate Slim into her image of a rock and roll savior. Slim, at first intoxicated with the idea and beguiled by Cavale, finally has to tell her that he can’t realize her dream. Slim Shadow goes back into his own world, his family, his responsibilities, leaving Cavale alone, setting her free.