Michael Franti is 6'6" and thin -- wiry, some might say. Long dreadlocks peek out the front and back of the hat he customarily wears onstage, but they never seem to stay contained. They can't, really, with all the jumping and dancing he does during a concert, alternately grabbing the microphone to sing and rap or strumming a guitar that looks almost unnaturally small in the big man's hands.

You might see Franti -- the frontman of politically active and socially conscious hip-hop group Spearhead -- and think that he should be a basketball player. Truth be told, not too long ago, Franti was just that for the University of California at San Francisco. "Sports really provided me with a work ethic that has carried out through everything in my life," he says. "So when I first got involved in music, first it was kind of a hobby, then I decided it was really what I wanted to do, to tell the world my story, to become a voice."

Franti and Spearhead are currently on tour with Ziggy Marley, the son of the late Bob Marley, one of the founders of reggae music. The pairing is an obvious one -- two bands playing socially conscious music that expands beyond the boundaries of whatever genre they're supposed to be in.

"Ziggy and I share a similar vision that music has a potential to be a healing force in the world," Franti says. "Though our music is different, we hang out, we play soccer, we've been working on writing some songs together. It's unusual for us to spend that much time with a band we're on tour with ... [but] I've known Ziggy for seven or eight years. I'm really proud of the fact that he's continued to stretch the boundaries and go into other music and styles. That takes a lot of courage and determination, and I admire Ziggy just for being himself."

It is the socially conscious message that Franti and Marley share that has led Franti, and Spearhead, to where they are now. "As a kid, I grew up never really feeling like I fit in with the family I was raised in," Franti, who was adopted, says. "Because of that, I've always had a larger definition of what family means. Family doesn't mean just mom and dad and kids and a dog. It's the community, it's the world."

That awareness pushed him to start reading poetry at UCSF, it pushed him to start his first band, the Disposable Heroes of Hiphoprisy and it pushed him to Spearhead. "When you get people dancing and listening to the lyrics, it's a powerful combination," he says. "I try to make records that are listenable from beginning to the end. We try to make it as uplifting as possible and also as sweaty and danceable as possible."

Catch Spearhead and Ziggy Marley on Feb. 27 at the Electric Factory. $24 and $26. More info at www.spearheadvibrations.com.