These days, it seems that innovation outpaces our ability to understand what it is doing to us. As Californians, we are used to tectonic shifts, but the ground beneath us is now in a constant state of flux. There are new means of transportation, communication and expression; new ways to meet people, new ways to smoke, new ways to listen to and consume music.

All this leads us to question what exactly constitutes “jazz” in the 21st century. The quintessential American art form is now more than 100 years old. While it was rebellious and celebratory in the early to mid 20th century, is that true today? Or has it become something else, changed forever by the shifting flows of time and culture?

Truthfully, jazz has been at something of a crossroads for a long time, its meaning hotly contested for decades. Some will say Miles Davis’ electric band wasn’t true jazz due to its rock & roll instrumentation. Others will say not only was that jazz, but the harmonically dense prog of British rockers Soft Machine falls under the same umbrella. And what are we to make of Norah Jones’ piano-pop album Come Away With Me, released by heavyweight jazz label Blue Note in 2002? Does its label define the genre?

The fact of the matter is that the meaning of jazz is under constant negotiation. At this year’s Winter Fest, San Jose Jazz has brought together some incredible artists who fundamentally challenge the definition of the genre. Below are some of the best artists on display at this year’s Fest: the dreamers, stretchers, and border-pushing musicians of 21st-century jazz.

Gilles Peterson

Feb 14, 9pm, $30
The Continental, San Jose

More than anyone on this list, the question of “Is this jazz?” applies most obviously to Gilles Peterson. A DJ by trade, Peterson does not play an instrument in the traditional sense. Instead, he was an early innovator of the genre called “acid jazz,” fusing familiar jazz sounds with Latin dance, Brazilian psychedelic, hip-hop and electronic synthesizers, all through spinning and sampling. Known for pulling out dusty deep cuts from all corners of the world, Peterson won’t be selecting music that falls squarely in any one category. In this sense, his work embodies the exploratory, and world-traveling nature of jazz music.

Bells Atlas

Feb 15, 10:30pm, $15
Cafe Stritch, San Jose

Oakland’s Bells Atlas compare themselves to a kaleidoscope, and for good reason. Led by the dusky vocals of singer Sandra Lawson-Ndu, there are times they could be confused for a pop band. However, those moments are fleeting—disappearing as quickly as they materialize into the night, along with the bob and weave of percussion, mallets and darkly shimmering guitars. If anything, Bells Atlas resemble the weirdo world pop of groups like Haitus Kaiyote. They are equally influenced by R&B, electronic, soul and jazz. Smooth without being smooth, Bells Atlas will tick a lot of boxes for jazz fans, while pushing them in a distinctly new direction.

The Bad Plus

Feb 21, 7:30pm, $30
Cafe Stritch, San Jose

The Bad Plus are a picture-perfect example of the many contradictions and possibilities of 21st-century jazz. It’s been 15 years since the Minneapolis trio (piano, bass, drums) released their iconic cover of Nirvana’s “Smells Like Teen Spirit,” and the DNA of that track is now firmly entrenched in the gene pool. Though not the only jazz cover of “Teen Spirit” (or even the first—Josh Roseman beat it by two years), it was considered borderline heretical at the time, almost a millennial prank. These days flirtations outside genre lines are now more acceptable, but that’s due in large part to the Bad Plus themselves.

Chéjere

Feb 22, 8pm, $20
Art Boutiki, San Jose

While jazz began in North America, the musics of South and Central America (as well as the Caribbean) have always been an indispensable part of the genre. Hailing from Mexico, Chéjere play a Central American version of the Afro-Cuban genre of “son,” creating a sound that is pan-American, reflective of the full diversity of the Western Hemisphere. Acoustic and polyrhythmic, Chéjere boast beautiful vocals, intoxicating musicianship and a welcome expansion of the meaning of jazz around the world.

The question for an artist like Rupa Marya must be: what do you do when you’re so well known for your unpredictability that it threatens to become predictable? Her sold-out show Sunday with her band Rupa & The Fishes—the finale of what appears to have been an extremely successful Winter Fest for San Jose Jazz—revealed the answer.

At this point, Marya’s music has been accused of every kind of border violation—smashing, crashing, stomping, flaunting, etc. Believe me, she loves this. But it also means that more people who go to her shows are ready for her mash-up of musical traditions, genres, languages and whatever else. Gypsy jazz cut with, say, cumbia and a wicked spaghetti western horn line may not be enough to get them high anymore.

That could be a problem, since Marya and her band clearly feed off that element of surprise, the energy that the audience bounces back at them when they’re creating something new, subversive, unheard. There’s an almost sexual element to it, not just because of Marya’s sultry performance style, but also because the band whips through a Kama Sutra of world music, and both performers and audience get caught up in the sheer boundless exuberance of it.

They’re finishing up their third album right now, and it was interesting to see Sunday night how the new songs toy with the expectations that have been put on the band. Rather than devolving into a sound-alike string of songs that drag every culture under the sun in kicking and screaming, Marya has broadened her range, juxtaposing songs that sound much more traditional to American audiences with her signature wild musical imagination.

The opening song, “Build,” was a good example of this. Sung in English and expanding exactly the way the title suggests, it was pure, smartly arranged indie folk. Then she launched into her patented global-freak-jazz style for the next few songs—part Django, part travelogue, part Occupy camp.

One minute she’d do “Inheritance,” which is almost twee folk, and the next she’d cover the Clash’s “Guns of Brixton,” launching into a Patti-Smith-like diatribe about the world economy as a gambling operation out to bilk us all. Then just when it felt like I might have my geographical and stylistic bearings, she’d turn a ’50s Bollywood song into a call-and-response rockabilly number.

Speaking of the Clash, I particularly liked “Electric Gumbo Radio,” which I believe is a new song. It’s a powerful take off on “This is Radio Clash,” with insistent ska guitar and lyrics of resistance that serve nicely as Marya’s mission statement, or declaration of war, or however you choose to look at it.

The audience, which was buzzing even before the band took the stage at Theatre at San Pedro Square, was enraptured with Marya, and why not? A passionate performer who can go from a stomp to a waltz to a whisper and back again (as on “L’Elephant”), she needs to be experienced live. In choosing her as a headliner to define the eclectic urban chic of their newest festival, San Jose Jazz made a perfect pick.

Rupa Marya calls her style “intentionally unclean.” Beyond that, it’s difficult to explain. Cooler and crazier than useless phrases like “world music” could hope to describe, her San Francisco-based band Rupa and the April Fishes takes gypsy jazz on a punky, border-crashing joy ride that sprawls across multiple styles, cultures and languages. Of Indian descent, born in California with an international upbringing, Marya takes the influences she’s absorbed and makes a particularly intense brand of dance music. She took the time to do an interview in advance of her upcoming performance headlining San Jose Jazz’s Winter Fest 2012 on Sunday, March 11.

STEVE PALOPOLI: Your music and style has a distinctly bohemian vibe to it. What appeals to you about that sound and look, and how did your musical style develop?

RUPA MARYA: It’s more intentionally unclean than necessarily bohemian. I appreciate the sounds of intersection, of things moving against each other–different gestures sonically. The mixture of symphonic culture with street culture, here with there, past and present. Music becomes a pastiche collage where you can trace different origins with your ear. I also appreciate the long history of rebel music, sounds that are responding to current injustice with insistence and courage.

In what ways is the Bay Area a good place to play the kind of music you play, and in what ways is it a difficult place?

I feel this music is a representation of the pluralistic identity of the Bay Area. On any given day, walking down Castro Street in Mountain View, you can hear several languages being spoken, sounds from different cultural backgrounds blaring from different cars. Our experience here is just that, an experience of pluralism. The challenge is how do you overcome the small-mindedness of people who want to believe the Bay Area is something else–such as an English-only place. It simply isn’t. How do you invite people with that desire to see the world in a simplistic way, to recognize the existing differences without fear but rather with open ears, arms, eyes and heart? I think some people appreciate hearing a celebration of these intersections, an invitation to shared space of engagement through sound and performance.