Warren Leight's largely autobiographical play told of growing up the child of an emotionally distant musician and a frustrated, fiery-tempered mother. As depicted by the younger Leight and played by Frank Wood (in a Tony-winning portrayal), the play's father was an unconsciously insensitive solipsist, unintentionally neglecting his wife and child in his devotion to music—the single beacon of guiding light in his foggy existence.

Donald Leight's story became known to thousands of theatregoers when a small Off-Broadway production of Side Man was singled out for praise, resulting in a transfer to Broadway's Roundabout Theatre Company, then a move to a commercial Broadway house. The part of the mother was originally played by Edie Falco, then a struggling unknown. (Warren Leight's mother died in 2003, reported the Times.)

Along with winning the 1999 Tony, the play was also nominated for a Pulitzer Prize.

"A lot of people have families with dysfunction in them," Leight told Playbill at the time. "I was just lucky my family's dysfunction paralleled what was happening to jazz. While the family unit was declining, so was the jazz world. It gives both worlds a richer context.... After the play, people come up to me and go, 'That was my father up there,' and I say, 'What did he play?' They say, 'Oh, no. He was a stockbroker. He always hid behind a newspaper.' Turns out, a lot of people have had the experience of caretaking their parents, either as kids or now as adults."

According to the Times, Donald Leight was born on Feb. 7, 1923. From 1948 to 1950, he was a featured soloist in the Buddy Rich big band and later played with Woody Herman and Claude Thornhill. He also found work in New York's swankier nightclubs—such as the Copacabana and the Persian Room—backing up the likes of Frank Sinatra, Lena Horne and Sammy Davis, Jr. Talking to Playbill On-Line about Side Man, Warren Leight said the play had been his dream project. "In some strange way, I had wanted to write about that world. I wanted to capture those guys, and capture the loss of that world and how hard that world was. So, not that I'm without dreams right now, but that was pretty good. It felt like a monkey off my back when I finished the first draft."

Warren Leight's father attended a performance of Side Man and, though he was not depicted in a terribly complimentary fashion, later said he had enjoyed the play. His initial reaction, however—in keeping with the way he had lived his life— was to focus on the musical aspect of the story. Said Warren: "The first thing he said was he was up all night, trying to figure out who the trumpet player played on 'I Remember Clifford.' "