The story is so suspiciously serendipitous that you'd swear it was concocted by a PR agent.

Hearing that guitar hero Derek Trucks was looking for a new singer, two producers independently sent copies of an album by Scrapomatic to Trucks' New York hotel room. The day he received the discs, the guitarist headed to a recording studio and who should he run into on the subway platform? The lead singer of Scrapomatic, Minneapolis native Mike Mattison.

"It's absolutely true," said Mattison, who was then an editor at a Manhattan PR agency and is now lead singer of the Derek Trucks Band. "I had an unwieldy Afro at the time and he recognized me from the two CDs. He said, 'Hey, we should get together and play.' Derek and some of the other guys [in the band] like to embellish the story and say 'We saw him playing in the subway and he was homeless.'"

Working with Trucks' improv-oriented band means the singer is actually a sideman. "You're just part of the ensemble -- you do your bit and step back and let everybody else do theirs," said Mattison, 40, who will return on Friday to the Minnesota Zoo with Trucks, 30. "It's fun to not have to carry the weight of the entertainer."

Mattison studied piano, clarinet, saxophone and French horn in elementary school while growing up near Pearl Park in south Minneapolis before getting serious about string bass. While attending Breck, he immersed himself in the Twin Cities music scene.

"I was definitely into the punk-rock scene with all the hometown heroes: the Replacements, Soul Asylum, Hüsker Dü and especially Prince," he said. "The fact that the national spotlight was on Minneapolis made it seem that it was possible to do your musical thing and make it -- and it wasn't just one style of music. It was a great melting pot happening, a great coming of age."

He headed to Harvard, hoping to become a comedy writer. Instead, after earning a degree in English and American literature in 1991, he moved to Hungary, where he sang jazz standards in clubs for a year. When he returned to Minneapolis, he taught ninth-grade English at St. Paul Academy, wrote jazz reviews for the St. Paul newspapers and sang in such groups as Who Are Those Guys and Scrapomatic.

He and Scrapomatic partner Paul Olsen decided to try their luck in New York. They took day jobs (high school teaching, then PR for Mattison) and managed to record three Scrapomatic albums. In 2003, Mattison had his serendipitous encounter with Trucks, and, after eight years in New York, relocated to Atlanta in 2005.

With Trucks, the singer tries to take on the character needed for each song, whether it's blues, jazz, R&B, gospel or rock. Mattison has made one live and two studio albums (including this year's "Already Free") with the 15-year-old Derek Trucks Band.

The singer hasn't given up on Scrapomatic. The duo -- Olsen still lives in Brooklyn -- does 30 to 40 gigs a year, usually when Trucks is working with his other band, the Allman Brothers. "We'll be picking up again in August/September," Mattison said of Scrapomatic, "and hopefully record our fourth record around October."

Jon Bream • 612-673-1719