A THEATREGOER'S NOTEBOOK

The only brightener in the dark, stark world of Warren Leight's Side Man resides happily in the comedy provided by Michael Mastro as a funky trumpeter named Ziggy -- or, as the character would say, Shiggy. "That's Ziggy with a bilateral lisp," Mastro volunteers. "Warren wrote into the play that the character speaks with a lisp. It's actually written. Every single s in the script for me has an sh."

In a crowded field of dysfunctionals, he stands out with his amiable awkwardness and ready humor. "I'm one of the people in the show whose job it is to bring levity to the evening. I enjoy that challenge. If I don't get a particular laugh, I go nuts."

None of the actors in Side Man play trumpet -- save for Frank Wood, who has mastered "Happy Birthday" ("We're all very, very excited for him") -- but they suggest that they do in small, subtle ways. Leight, who grew up in the jazz milieu, "watches us like a hawk to make sure we never hold or deal with the trumpet in a way that's unmusicianlike," says Mastro. "But we never play music. The only time you see the musicianship of these guys and their great love of music is when they trance out on a Clifford Brown record." It's Mastro's
favorite moment in the show.

Side Man is his third Broadway gig. He insists on counting the first, which occurred July 15, 1995. "I was understudying Mario Cantone in Love! Valour! Compassion! and got to go on for the matinee and evening." His second occurred only at curtain call: He was the offstage voice that fed Christopher Plummer's Tony-winning Barrymore. After Plummer thanked him in his acceptance speech, "There were 20 messages waiting on my answering machine." Reflected glory is nice, too.