In the quarter-century that hip-hop has been in the public eye, it has evolved from groups consisting of a rapper and a DJ into a genre where traditional DJs, break-dancers and graffiti artists are hard to find among all the jewelry, cars and bouncing booties filling rap videos.

The X-Ecutioners are here to change all that.

The three-man DJ ensemble -- Rob Swift, Roc Raida and Total Eclipse -- first formed in New York City in 1989 with the intention of becoming a DJ "band" ready to compete in DJ battles in hip-hop's homeland. Fifteen years later, though, the goal is more ambitious as the group releases its second major-label album, "Revolutions."

"The main goal that we had with this one was to once again figure out a way to expose the idea that the DJ is at the nucleus of hip-hop culture and music," Swift said. "We feel that we've been in this fight to expose that on a wider level because a lot of the rap music you hear these days, you really don't feel the presence of the DJ in the majority of it. You rarely get to hear scratches on records these days, and you rarely see the DJ in a lot of rap videos.

"We feel it's our responsibility as DJs, being influenced by the greats like Kool Herc and [Afrika] Bambaataa, to project that image of the DJ and to show people that we haven't gone anywhere, that we're still here and that we are an important part of the music."

After experiencing the X-Ecutioners live in concert, there is little doubt how important the DJ is to hip-hop, or how entertaining three DJs on one stage can be, with nary a rapper in sight. Swift, Roc Raida and Total Eclipse work out intricate routines that feature body contortions and finger play that is hard to believe, with each DJ treating his two turntables as an instrument and songs being built up in a series of traded "riffs" among the players, just like a jazz combo or hippie jam-band might.

"It beats going to a show and watching a guy rapping, walking from side to side onstage for an hour," Swift said. "When we play live, we're the kind of group that likes to execute what we practice, so the majority of the stuff we do isn't improv in our live show. But we've been thrown in situations where we've had to. The turntable is an imperfect machine. It can mess up on you. "

While the X-Ecutioners are a live act, to be sure, they make fine albums. "Revolutions" is an 18-track journey that will sound great bumping from car speakers all summer. The album is a follow-up to the X-Ecutioners breakthrough, "Built from Scratch," an album that reached No. 15 on Billboard's album-sales chart and boasted an MTV and radio hit in the Linkin Park-aided "It's Goin' Down." That album's release roughly coincided with "Scratch," the Doug Pray documentary on the history of turntablism that prominently featured Swift and his spinning, scratching brethren. The movie played at Sundance before a theatrical and cable run, and Swift credits it with helping bring DJs into the limelight.

"It's been running on cable, Independent Film Channel, Showtime," Swift said. "People in Idaho and Wisconsin that have these channels but don't necessarily know where to get into hip-hop can sit at home and learn about DJs like Q-Bert. The movie definitely played a major role, and I think our album 'Built from Scratch' was a pivotal album in getting the awareness out there. . . . That's something we've always tried to do -- expose the art form."

It's an art form that's grown by leaps and bounds since Grand Wizzard Theodore was heard scratching on Herbie Hancock's MTV hit, "Rockit," unwittingly launching a thousand DJ careers in bedrooms across the country. Competition between DJs, rappers, dancers and graffiti artists during hip-hop's adolescence kept the genre from stagnating, and that same competition still drives Swift and his peers in the X-Ecutioners, sometimes even within the confines of the group.

"The whole nature of hip-hop music is, 'Who is the best rapper?' " Swift said. "Who is the best DJ? Who has the best sound system? Who break-dances the best? And the whole point is not necessarily to embarrass anyone, but that's how the art progresses, by the battling, by who's better than who. That's how the art changes and grows. Within the group, there's a friendly competition. If Total Eclipse comes up with a routine, I praise him for it, but automatically, after he leaves my house, I'm thinking, 'Alright, I need to come up with a routine.' "

When it comes to DJ collectives, there is no competition for the X-Ecutioners, in terms of longevity, commercial success or creativity, and they do it with the same basic elements as the DJs first creating the form in 1980, with no bells, whistles or computers.

"A lot of DJs, they call themselves DJs, but they don't really use turntables, or don't use them to their full capacity onstage," Swift said. "The X-Ecutioners, we're traditional DJs, man. You're going to see us up there with six turntables, a mixer, and whatever happens, happens."

The X-Ecutioners, The Streets with C-Rayz Walz and The Pharcyde perform tonight at Park City's Harry O's, 427 Main St., at 9 p.m. Tickets are $18, available at all Smith's Tix outlets and the door.