Roll over Stradivarius

His blond-streaked black hair flails about. The horsehair of his bow flies, as it saws against the screaming strings of his violin. Onstage, Bobby Yang transforms into a leaping fireball that spews blazing, virtuosic rock music. No tepid crossover pabulum from this classically trained prodigy. Yang is the real thing, and the raw expressive energy of rock is as much the core of his musical soul as Mozart, perhaps more so.

His debut CD, No. 1 Tribute, released last summer, pays homage to that soul: all cover tracks, it ranges from Led Zepplin’s “Kashmir,” to Guns N’ Roses’ “Sweet Child O’ Mine” to Smashing Pumpkins’ “Cherub Rock.”

Like his hair, 27-year-old Yang is a study in contrasts. Off stage, he is soft-spoken and friendly, but driven and quietly determined.

At a rehearsal in early December, Yang arrives first. He lifts his violin from its case, repositioning the E-string and apologizing that his “No. 1 ax” is still settling in, just back from repair of minor climactic damage that comes from touring. The rest of his Unrivaled Players arrive — guitarist Clay Cook, bassist Rob Henson and drummer Mark Cobb. They quickly get down to business preparing for a gig in Los Angeles. In 50 minutes they nail the outlines of 10 new songs onto their playlist — no charts, all ear and memory. Led Zepplin’s “Ramble On,” some Jimi Hendrix and a handful of ZZ Top songs are among them.

Yang grew up listening to classic rock, but received intensive classical training in violin. Annual trips to the Aspen Music Festival inspired Yang to use his violin to challenge electric guitars as the reigning stringed instrument of rock gods. “I started hanging out in Aspen in the summers, playing rock music at night, taking classes but not being involved in the orchestras,” says Yang. “So I decided to stick around after I graduated.”

He found Aspen an ideal place to woodshed, sitting in with whoever came through town in the local clubs as many as five nights a week. “I felt local and cherished,” says Yang. “People wanted me up on stage for hours at a time. In New York, you’re lucky if you get up for half a song. They give you a solo, the crowd applauds, and they kick you off stage.”

Eventually, Yang began to feel land-locked and decided to move. New York City was his destination; Sept. 12, 2001, his targeted date of arrival. But the attack on the World Trade Center the morning before changed Yang’s plans.

“I gave Chicago a chance, I gave Los Angeles a little bit of a chance,” says Yang. Then Atlanta beckoned him in 2003. Rather than play the local clubs, Yang began working Atlanta’s studio scene. Initially he worked on some hip-hop tracks, but he had problems getting paid. “I was a little bit disheartened. I actually had hip-hop producers say, ‘You think you can just come into Atlanta and we’ll roll the red carpet out for you?’ [then] stiff me for the money.” Times got so tough, he had to sell his ‘71 Chevy Chevelle. But hip-hop’s loss was rock music’s gain. Eventually, Yang began creating string tracks for acts such as Avril Lavigne, and making limited appearances at outdoor shows, sporting events and parties. More recently, he and his Unrivaled Players have performed live on local radio — 99X, Star 94 and 96 Rock.

Though Atlanta may just now be discovering Yang, Hollywood already knows him. He performed at Kevin Costner’s wedding in 2004, and Bruce Willis offered the blunt compliment: “Bobby Yang is fucking awesome!”

That awesomeness comes partly from his onstage enthusiasm for the music, and partly from overcoming the technical boundaries he pushes to express it.

“I’d be nothing without my bowing,” says Yang of the rock techniques he found and explored on his own. “I happened to get lucky. I just became obsessed with violin technique, and I took it farther,” he says, producing expressive sounds that are unacceptably “ugly” by traditional classical standards, but which are ubiquitous in rock.

Though he experiments with technique, he’s a purist when it comes to choice of instrument. Yang’s full-on rock sound is all acoustically produced, entirely made with fingers and bow. He allows himself straight amplification only, with some reverb. No plastic, simulated violin-like objects for Yang, or array of plug-in effects — in defiance of current fashions in the glittery side of the urban and rock, where purple “flying V” electronic violins are considered cool and hip.

Yang plays an amalgamation of vocal lines and lead guitar parts, improvising away. Not limited by lyrics, the music can go almost anywhere, and the band rolls naturally with the flow of the moment as Yang, responding to the audience, can suddenly take off on an intuitive musical tangent. “The soul of rock ‘n’ roll,” says Yang, “is really feeling the crowd and being able to translate that perfectly into music.”