"Whenever you're on stage, at least 50% of you is in the audience." - Maria Callas

Anyone that follows the new music scene here in New York is no doubt familiar with violinist/composer Caleb Burhans. With his piercings, black nail polish and peacock-high hair, he certainly cuts an unusual image for a classical musician.

"I used to be into punk as a kid. That's when I got all these piercings. But, then I found out about Stockhausen and Xenakis, and I was like: Wow, this shit is really hardcore. That was it for me."

Burhans, 28, is perhaps best known as the lead violinist in new music ensemble Alarm Will Sound, with whom he's been playing since his Eastman days. Alarm Will Sound filled Zankel Hall Thursday night, with an eclectic, physically demanding program that had Burhans crawling around the ground in Gyorgy Ligeti's Chamber Concerto (1970) and singing countertenor in Johannes Ciconia's Le Ray au soleyl (1402).

Burhans was at his best, however, when allowed to sit still for the two most challenging works on the program: Harrison Birtwistle's Carmen Arcadiae Mechanicae Perpetuum (1977) and the NY Premiere of John Adams' Son of Chamber Symphony. (It probably helped that he didn't have to play from memory.) Even from the back of the mezzanine, I could feel his ferocious energy in the Birtwistle, attacking the violin like a piston. Conversely, the Adams featured an extended solo for violin in the central movement, which Burhans played with heart-rending tenderness.

Burhans told me that he once played for Birtwistle, who paid him an enormous compliment: "I'm glad to see someone having fun with my music for a change."

"My dad used to play violin," Burhans said, "and he always used to tell me what Ray Charles said to him: 'Performing is 10% hearing, 90% seeing.'"

But, Burhans is a far more versatile musician than his concert at Carnegie would indicate - out of necessity, as well as personal preference. Last week alone he had no less than five separate gigs - plus he sings every Sunday morning in the choir at Trinity Church on Wall Street. Somehow, he even manages to squeeze in time to compose and arrange for various ensembles.

Still, I don't think anything quite prepared me to see him onstage the following night at Southpaw with Escort, hands down the hottest Disco band in New York. Yes, Disco. Led by Donna Summer-lookalike Zena Kitt, they packed about 18 people onstage, sending the diverse crowd into a swarm of dancing. Burhans played in back, but contributed a couple of out-front solos that were spot on. "It wouldn't be Disco without those strings," one friend said to me. "That's what makes it." Burhans, for his part, seemed to be enjoying the party.

You can catch Burhans in all his various guises over the next few weeks. He's singing Haydn masses with the Trinity Choir next Tuesday, playing with Alarm Will Sound on March 21 & 22 at The Kitchen, and performing blissed-out low rock with itsnotyouitsme on the next Wordless Music Series bill. (itsnotyouitsme also plays St. Peter's Church on 3/28 and The Tank on 4/9.) No word on when the next Escort gig is.