Peter Guertin's keyboard is a mainstay at the Brave New Workshop

When Peter Guertin first sat down to tickle the ivories at the Brave New Workshop, George the Elder Bush was beginning his presidency and Dudley Riggs still ran the Workshop. This weekend, Guertin opened a show with a director who was in high school when Guertin had started and with actors who were grade-schoolers then.

"It's still enjoyable, a steady gig with a paycheck every week," said music director Guertin, more amused than amazed by his longevity. He feels old only when he makes a musical reference that everyone would have understood 10 or 12 years ago but now draws quizzical looks from young actors.

Although he dropped in and out during the 1990s, Guertin, 49, has been at the keyboard -- composing and playing for each show -- full-time since 2000. He has noodled countless songs about Prozac, religion, politics, sex, work, heroes and has-beens. As old mates have run off to great things in L.A., or left show biz entirely, Guertin has remained at the Workshop -- the Methuselah of 2605 Hennepin Av. S.

He got his first taste for the stage when he dressed up as Elton John for a talent-show skit in high school in Plymouth.

"To this day, I still get comments from people who saw that: 'You're the Elton John Guy,'" he said. "My life sort of peaked then, and it's been all downhill since."

He bounced around at the University of Minnesota and then St. Cloud State. He returned to the Twin Cities and, after a few auditions, became the Workshop's music director.

"It was really competitive," said the piano man, who also does club gigs with rocker Mick Sterling. "A lot of people wanted the job."

Hum me a tune

Guertin's favorite stuff for Brave New Workshop shows is the incidental music that will underscore a scene or provide an accent. But he's also there to put together songs, which are more plentiful in "Toyota! The Runaway Musical Hit" than has been the case recently. Director Katy McEwen said the show isn't a classic musical, but every scene will have something tuneful. That brought Guertin in on the process earlier than usual.

"We'll bring our lyrics, hum a melody, give him the style and feel, and he'll just start to play," McEwen said of working with Guertin. "He'll play, you sing, and it just happens."

Asked about top shows through the years, Guertin quickly mentions "Das Bootylicious," a 2004 piece featuring McEwen and Shanan Custer.

"There was not one song in that show that I would ever cut," he said. "We wrote them all in one night. That was one of my favorite times."

In 1991, Guertin stretched his vocal cords for the first and only time, singing "White, Straight Male," written by Peter Staloch for "Politically Correct Means ... Always Having to Say You're Sorry."

Ah, those were the days, when he was young and foolish.

"Sometimes I wish I was 20 years younger and knew what I know now," he said.

Yeah, don't we all.