Some actors spend entire careers trying to buck their iconic screen identities and avoid type-casting, but Lieutenant Da — er, Gary Sinise — has embraced his Forrest Gump persona, reviving it, with bass in hand, in a 12-piece, multi-genre group that has become a fixture on both the club and USO circuits.

The band, named after the bristly Vietnam-era commander-cum-shrimp boat first mate of Gump fame, is what Sinise describes as “a mixture of contemporary and classic stuff, a mixture of genres: rock, pop, country, blues — we mix it up pretty good. We could be going from a Beyoncé song to a Charlie Daniels tune. You never quite know what’s coming at you.”

Sinise has done a lot in the 12 years since asking Forrest if he’d found Jesus yet. He is a regular on the popular CSI: New York series, playing Detective Mac Taylor, a former military man and 9/11 widower. And perhaps Sinise’s reputation as an award-winning director and co-founder of the celebrated Steppenwolf Theatre Company in Chicago precludes him from being pigeon-holed into former roles. “This is what I do for fun,” he says of the band, “I work on CSI and when I put the bass in my hand, and get together with these musicians, we just put on a good show.”

The genesis of the band is a simple story as Sinise tells it. “When I was doing a play in ’97, the composer, Kimo Williams, heard that I used to play bass and he invited me over to his house to have a jam session. We hit it off.” They assembled a diverse crew of musicians — “most from Chicago, which is where I grew up” — and with all the normal band fixings, added three vocalists, a trumpet player, a keyboardist, a sax, a flute and the occasional violin player to form a dynamic cover band. “We’re a well-oiled machine at this point,” says Sinise.

In addition to his music career, in the last decade, Sinise has gone on multiple USO tours to entertain U.S. troops. “I volunteered shortly after Sept. 11, right around the time we went into Afghanistan, and then my first USO thing was actually a band gig in Chicago where we just invited a bunch of sailors and Marines from Great Lakes Naval Base to come to the National Vietnam Vets Art Museum. We just threw a party for some of the local folks there. Then I went on my first tour to Iraq with a lot of entertainers — Kid Rock, Leanne Womack, football players, basketball players, cheerleaders, the whole thing — then I went back to Iraq again about six months later. Eventually I asked if they would let me take the band with me.”

It was during one such USO tour that Sinise visited a local school and was struck by how abject the facilities were. “I started sending school supplies over when I got home,” he says, “I wanted to send them to the troops to give them out there.” This endeavor became Operation Iraqi Children, an organization he co-founded with best-selling American writer Laura Hillenbrand, author of Seasbiscuit: An American Legend. “She had a project she was working on to translate Seabiscuit into Arabic and to give it to some people over there,” Sinise remembers. “We had a mutual contact [in Iraq], a major who thought that Laura and I should get together and possibly team up.”

He remembers an e-mail he later received from Gudrun Scott, a registered nurse who spent her childhood in World War II Germany. Scott recalled the impact that simple gifts from the U.S. during the war had on her: pencils and bars of chocolate were invaluable to a 6-year-old child. She applauded Sinise’s efforts. Sinise says, “I was inspired by that. It’s similar now. In World War II we bombed out, just devastated all of Germany, cities were just demolished, and when the troops just walked through those cities, kids would come out of those bombed out buildings … here are the people who just bombed the cities just handing out things.”

“I’m going to go [to Iraq] by myself again at the end of April, and the band at the end of May is going to do a 10-day bus tour where we hit four or five [U.S.] bases,” he says. Asked what someone can expect from the band at their upcoming Canyon Club gig, he replies with the no-bullshit Lieutenant Dan edge, “You put on your dancing shoes and get out there and rock and roll.”