Even as they creep up on middle age -- how can it be feasible that these guys are pushing 40? -- the Beastie Boys remain uniformly skilled at raucously "rocking a block party till [their] hair turns g

Even as they creep up on middle age -- how can it be feasible that these guys are pushing 40? -- the Beastie Boys remain uniformly skilled at raucously "rocking a block party till [their] hair turns gray."

But even venerated veterans like the Beasties rely on a stash of banging beats -- and an onstage foil. Both roles are played again on the in-progress tour in support of the No. 1 album "To the 5 Boroughs" by Mixmaster Mike. "They call me the sparkplug of the band," Mike says by phone before a recent tour stop in Miami. "I'm in charge of all the outgoing mayhem."

The Beastie Boys are an unusual entity in hip-hop, one that functions as a band rather than strictly adhering to the unwritten two-turntables-and-a-microphone rules of the game. But musical mayhem has been Mike's domain since his earliest days, well before he was considered one of the planet's premier practitioners of the art of turntablism (legendarily, the scratch team of Mike and friend and fellow DJ Q-Bert ended up winning so many consecutive DMC world titles that they were asked to step down from competition).

A founding member of the Invisible Skratch Piklz, Mike -- along with Q-Bert, Apollo, D-Styles and Shortkut -- became part of one of the most influential turntablist crews ever. It didn't take long for the crew's success to catch the ear of Beastie Boy Adam Yauch, who asked Mike to provide studio work on the Beasties' 1998 album "Hello Nasty." Mike's answering-machine message, in which he pitches his services to the crew, is documented on the album's "Three MCs and One DJ," in a rare case where the turning point in an artist's career is caught live on tape. Soon after, he became the group's resident DJ, a job he revels in to this day.

"They give me the freedom to switch up the show as I go. They have full trust in what I'm gonna unleash and they're happy with it," Mike says. "I go from total hip-hop to a B-52's beat -- just for a brief moment, to catch them off guard. Or I'll throw in some Clash, or a Gary Numan beat out of nowhere, just to keep it interesting. The reaction on the guys' faces is so funny."

In addition to serving as the Beastie Boys' tour DJ, Mike maintains a solo career; his latest CD, "Bangzilla," is a more "sonically composed" scratchfest grounded in the wild style of '50s monster movies.

"I didn't mean to have a sci-fi thing," Mike says. "I was just sitting around watching a lot of B-flicks like 'The Blob' and 'Gargantua' and 'Gamera.' And I got inspired. I wanted to make something that'd never been made before: a monstrous instrumental album."

The art of turntablism, and Mike's particular brand of it, is grounded in improvisation and innovation. He draws on a background steeped in a lot of Miles Davis and Jimi Hendrix in shaping his routines. "A lot of [Davis'] tracks are based upon improv, and then going back to choruses," he offers. "And I learned that you can play an instrument freely without losing the crowd. I applied that whole thought. You can play the turntables the same way Miles played the trumpet or Jimi played the guitar. I try to push it forward and use the turntable as a percussive instrument."

That drive for innovation is a motto he's tried to adhere to since his days in the Piklz. "We took [innovation] upon ourselves when I formed the Piklz, [when] we formed the first-ever turntable orchestra," he says.

But after that, the role of the turntablist grew away from something novel and musically grounded into a bandwagon to be boarded. "It kinda grew a little corny, from my perspective," Mike admits. "I saw a lot of rock bands getting DJs, and it seemed like they thought it looked good, and it was the cool thing to do, adding that component. And from that you see DJs doing Right Guard commercials -- so corny."

Still, Mike isn't worried for the art form as a whole -- just that there aren't enough practitioners of it, a common argument you might find in any genre of music or art. "There's still not enough DJs such as myself or Q-Bert pushing the envelope and making turntable music," he says. "My goal is that when you walk into a Tower Records, you have enough of this music that you can look up hip-hop, soul and then turntable music.