Boston Globe, February 15, 2008

NEW YORK – He’s a self-described egghead, a numbers nut who could have become a mathematician or economist. He’s a science-fiction fan who loves William Gibson’s “Neuromancer” and is liable to zone out to sci-fi reruns on TV.

But when Rudresh Mahanthappa takes the stage, it’s with an alto saxophone, not chalk and blackboard, that he burrows into theorems and explores alternate planes, in a musical language so vivid and complex that hard-bitten jazz arbiters have dared to compare him to Ornette Coleman or John Coltrane.

Mahanthappa, 36, visits the Isabella Stewart Gardner Museum Thursday with his quartet, which includes pianist Vijay Iyer, a fellow Indian-American with whom Mahanthappa shares certain cerebral characteristics and enjoys an uncanny creative understanding. Bassist Francois Moutin and drummer Dan Weiss round out the unit.

Lavish praise for the quartet’s 2006 album, “Codebook,” along with his own regular presence in critic’s polls as a top “emerging” saxophonist – and, most recently, the award of a Guggenheim fellowship – have left Mahanthappa, who by temperament is modest and easy-going, no choice but to accept that he now dwells in the jazz spotlight.

“If this means I’ve emerged, I’m a little bit scared,” he says on a bright winter afternoon in his Brooklyn neighborhood. “I don’t feel like I’ve emerged yet. But maybe in the broader scheme of things, I have.”

Though Mahanthappa has a wide array of projects with different collaborators, ranging from avant-garde improvisation to encounters with Indian and Arabic classical forms, it’s “Codebook” that stands as his most thorough statement of arrival – as well as his fullest reconciliation of the analytic and emotional influences that make his work unique.

“Codebook” is, in a sense, a mathematical concept album. The compositional core of each song embodies some kind of cryptographic manipulation. The melody of one song reflects the Fibonacci sequence of integers; another involves manipulating what mathematicians call a cyclical number; some involve multiple layers of encoding.

When performed, however, the songs don’t sound nearly as abstruse as the setup might suggest. Quite the contrary: The burning intensity of Mahanthappa’s playing expresses passion far more than calculation, and if the sinewy twists and turns, the unexpected inflections, the aggressive pacing show an obvious appetite for complexity, the structuring device is unobtrusive, merely lurking in the music’s filigree.

That’s exactly as Mahanthappa intended, he says. “If someone told me that some music was math-based, I would immediately assume that it’s not really listenable,” he says. “That it’s going to be like what we used to call bleep-blop music, like a computer generating random noise. But the music’s always the most important thing, and I’m trying to make music that I would want to listen to and that I enjoy playing.”

Onstage, Mahanthappa’s presence is intense yet contained, graceful and generous to his bandmates. Offstage, he’s easy and casual. A wry playfulness leavens his analytic bent and extends into his composition: One song on “Codebook” begins with the players spelling out their names in the dots and dashes of Morse code. And an earlier quartet album, “Mother Tongue,” employs a wicked conceit: Frustrated with questions like “Do you speak Indian?,” Mahanthappa recorded indignant responses by various Indian-Americans in their families’ respective languages and set each one to melody.

Mahanthappa says he looks to devices like these to orient his work because he doesn’t see himself as a natural musician – his extravagant technique and talent notwithstanding.

“Looking outside of music for inspiration kind of keeps things fresh for me,” he says. “And maybe it’s because I never really felt like a naturally good musician, like one of those people that music just flowed out of. For me, it’s been half instinct and half intellect.”

Growing up in Boulder, Colo., the son of a physicist, Mahanthappa was well on track to go into science when he decided – to his family’s initial consternation – to pursue music instead. “There will always be part of me that feels like I jumped into this thing to almost make life hard for myself,” he says. “But because of that, I feel like I can bring something else to this music.”

Though he obtained top-notch training at Berklee College of Music and at DePaul University in Chicago, Mahanthappa, having grown up outside the jazz world, had to adjust to the culture surrounding the music. In Chicago, he says, being neither black nor white made him an unknown and potentially suspect quantity in the local jazz circles.

New York allowed him to finally traverse those barriers. “When I got here, I really felt that chameleon thing, where the black community treated me like one of their own, and the white community treated me like one of their own,” he says. “So I feel like I can slither in between these various cliques or larger groupings of musicians, without there being any sort of preconception before I actually put the saxophone in my mouth. The slate is a lot wider open.”

That openness has given Mahanthappa the comfort and creative space not only to advance his straight-ahead jazz projects, but also to manifest Indian influences more explictly than ever done before. One current project, Indo-Pak Coalition, is a trio with Pakistani-American guitarist Rez Abbasi and percussionist Weiss on tabla. But Mahanthappa’s most intense focus is on deepening his understanding of Carnatic music, the classical tradition of South India. He’s between trips to Chennai, the center of Carnatic music, where he’s been taking in concerts and studying with masters. And he’s about to release an album with Kadri Gopalnath, who pioneered the use of the saxophone in orthodox Carnatic forms. The two played a pair of sold-out shows to a largely Indian audience at the Asia Society last year.

Mahanthappa’s investment in Carnatic music represents a cultural homecoming for this otherwise highly Americanized immigrant’s son, who grew up with jazz and sci-fi and basketball and admits to being largely inept in Kannada, his family’s language.

“That was always a sticking point,” he says. “`How Indian can you be [if] you don’t even speak your parents’ language?’ But by doing what I do, I’ve inadvertently made up for that, because I’m speaking another language of my ancestry.”