Twyla Tharp is the world's most famous living choreographer. She is also famously cranky. In person, she is almost the caricature of prickly genius. Before our interview, her press liaison discourages questions about her 1992 autobiography but encourages questions about her 2003 self-help book. During the interview, Tharp counters any question about her most recent Broadway production—a critically lambasted evening of dance set to Bob Dylan songs—with flat refusal: "This is not a subject for this conversation."

She is curt and evasive when talking about any dance other than her own ("you'll have to ask them" is a favorite rejoinder) but witheringly loquacious about why it's a good thing that theater and dance critics are being fired wholesale from American newspapers: "Very few journalists, critics, or writers in any arena of the arts have the depth of information to give any fodder for thought."

For any thought?

"For healthy thought."

But the 67-year-old artist, who has come to Seattle this month to make two world- premiere ballets for PNB, has earned the right to be ornery. She is not only the most famous living choreographer—she may be the most influential.

Tharp structurally rearranged the dance world in the early 1970s with her ménage à trois of classicism (ballet), avant-garde (minimalism), and pop (rock 'n' roll and jazz). This brought her both artistic and commerical success, though not always at the same time. An early artistic triumph: Deuce Coupe, a 1973 dance for the Joffrey Ballet set to music by the Beach Boys. Later commerical trimphs: Broadway hits (Movin' Out with music by Billy Joel) and film credits (Hair, Ragtime). "She was one of the first to put many influences in her choreography," says PNB artistic director Peter Boal. "Ballroom, tap, kickboxing, pedestrian movement."

Tharp is relentlessly democratic. And because of Tharp, choreographers have been pulling pop culture into the studio—with mixed results—for decades. Which is why it is surprising to hear Tharp refuse to comment on how the dance world, which she profoundly shaped, appears from her perch at the top:

"I work, I do what I do, end of story," she says.

You don't see other contemporary dance?

"I work."

Do you ever see dance?

"I work."

So you don't have any idea what other choreographers are doing?

"I work."

Does that work involve any homework?

"I read a lot. I've been reading 19th-century novels. I've read all of Proust, all of Tolstoy, and I'm currently reading all of Balzac. I've read Stendhal, Flaubert, George Eliot. I'm a serious reader."

Are you just not interested in other choreographers?

"I work—hello?—I work!"

It's difficult to believe she's that hermetic, and a pity if she is. Tharp might enjoy seeing what her revolution has wrought. Two performances last weekend exemplified how far contemporary choreographers have tried to advance Tharp's charge.

The Snow Project, by Seattle choreographer Allison Van Dyck, is a young and flawed heir to Deuce Coupe: It is iPod minimalism, cool and slick with a faint human pulse. In the quicker sections, the four dancers whiz across a plain white dance floor in metronomic phrases. The choreography is largely vertical, using tightly curved arms and legs for flourishes, like electrons spinning around a nucleus. The Snow Project is pretty but a little vacant. It is a dance of gestures rather than ideas. Depending entirely on the discipline of its dancers, it suffers when they wobble or have to think their way through the choreography. (Corri Befort, who dances like a strong, compact machine—with a human pulse—is the only one who never seems to falter.)

Tharp's democratic insistence on putting virtuosity and pleasure on equal terms has also changed European choreography, as evidenced every year by companies touring to On the Boards. In 2006, Berlin's Dorky Park drilled deeply into pop culture, discovering genuine pathos and humor.

Last weekend at OtB, Superamas—from Paris and Vienna—did not. Its BIG, 3rd episode (happy/end) was a shiny, lurid spectacle, the opposite of The Snow Project's cool detachment. A study of the commodification of happiness, BIG threw pop-culture clichés at the audience by the handful: clichés about gender (sexist dudes drinking beer at band practice, chicks at the gym obsessing about men), television (commercials, Sex in the City), performance art (a lengthy quote from Derrida), and so on. The only real dance passage in BIG was a three-minute nightclub dance-off to a Gnarls Barkley song. BIG was a hotter spectacle than The Snow Project but also pretty vacant. Its fusion of pop and avant-garde felt dishonest, like slumming.

At a reception after the show, one of male Superamas—Philippe Riera—explained, "We enjoy to bring things to the stage that are not usually artistically valued, like commercials and fashion." In this, he agreed, Superamas has been influenced by Twyla Tharp. "But," he said, "her dancing can be a bit academic." More academic than quoting Derrida to give your show ballast? He just laughed.

Which is why, after all these years, we still need Tharp's cranky rigor. Her democratic impulse made true partners out of the high and the low, insisting that we scrutinize pop with a new degree of seriousness and not let the avant-garde intimidate us with its austere priggishness.

But is her new work backing away from pop? Her recent European reading list and reluctance to discuss the Bob Dylan incident suggests so, as do her two world-premiere ballets for PNB.

The first, set to Brahms—the king of romantic seriousness—is described by Boal as a "traditional, balanced, and symmetrical" ballet. Tharp says the second, set to Russian minimalist composer Vladimir Martynov, "comes out of my bleak streak, wherein we have a bit of existentialist theater, shall we say, and the end of the world."

The evening ends with Nine Sinatra Songs, some light and witty ballroom vignettes Tharp made in 1982. Sinatra, apparently, is the coda to Armageddon. recommended