“I figured I’d better couch my diagonals and spirals in sex and surprise,” Twyla Tharp wrote in her 1992 autobiography, “Push Comes to Shove,” explaining her early approach to dance, and that description remains apt.

The 83-year-old New Yorker ranks among the influential and innovative dancemakers of her generation, creating more than 150 works that can be complex and conceptual but also cool and funky.

As vital and active as ever, Tharp is marking her 60^th anniversary as a choreographer with a high-profile, cross-country tour featuring her 12-member company, Twyla Tharp Dance.

In what is arguably the most anticipated event of the Chicago dance season, the company presented the first of three performances Thursday evening at the Harris Theater for Music and Dance, reaffirming it as Chicago’s pre-eminent dance venue. (Tharp was not in attendance.)

Given Tharp’s standing in the dance world, it is no surprise that she has put together a cohesive ensemble of supremely talented dancers for this tour who exhibit their own strong artistic personalities but also grasp her aesthetic and are totally committed to making it come alive.

Modern dance and ballet were once quite distinct, the first coming as something as rejoinder to the latter, but Tharp daringly brought the two together in works like “Deuce Coupe” (1973) and “Push Comes to Shove” (1976), and even merged her company with the American Ballet Theatre in 1988.

She has also explored such notions as order and disorder, and, ever the showwoman, she has created works set to music as adventurously varied as ragtime, Billy Joel, Frank Sinatra, Randy Newman and the Beach Boys.

Chicago has had an important place in Tharp’s history in large part because of her extensive collaboration with Hubbard Street Dance Chicago. Starting in 1989, the company added six of her works to its repertoire over 10 years and commissioned two others, including “I Remember Clifford” (1995).

Some Tharp fans were probably hoping she would present at least one of her early milestone works on this latest tour, but the choreographer instead opted to open the program with might be called a mid-career classic from 1998 — “Diabelli.” It is set to Beethoven’s solo piano masterwork, “Diabelli” Variations (performed live by Vladimir Rumyantsev).

This piece, originally for 11 dancers and presented here with 10, is a true ensemble piece, with virtually every performer getting equal time in the spotlight and the number and combination of dancers endlessly shifting.

It has a light, airy, even whimsical feel (accentuated by Geoffrey Beene’s humorous faux-tux unitards) with a few overtly comedic moments, like a slapstick bit when two of the men (Renan Cerdeiro and Oliver Greene-Cramer) keep trying to step in front of the other and even jostle a little.

Very much in keeping with Tharp’s penchant for stylistic crossover, this work contains elements of ballet (but no pointe work), modern, jazz and social dancing, including an open-hand wave reminiscent of the Lindy Hop.

The intricately interwoven movement can be highly athletic, like a woman swinging high on the arms of two supporting men as another woman twirls frenetically nearby, but also quite simple — a swivel, a swung leg, a bounce. But no matter how complex or basic, in what is another Tharp trademark, there is a sense of ease and fun about everything presented.

The piece runs nearly an hour, and it does start to feel a tinge long toward the end but it is never repetitive. Though elements are sometimes repeated, “Diabelli” remains constantly fresh and vibrant, and the short duration of each of Beethoven’s 33 ever-changing variations keeps the momentum snapping.

The work is essentially abstract, but interactions among human beings inevitably suggest mini-narratives like a handful of dancers who stand to the side in one section like party wallflowers with one whispering into another’s ear. And there are hints of romance in the duets like the sometimes tender interactions between Miriam Gittens and Alexander Peters.

Showcased on the second half is a new 35-minute work, “Slacktide,” that has much to offer on its own but was not well served by being presented right after “Diabelli,” because it comes off too much as more of the same.

The big difference is the music, an arrangement of Philip Glass’ “Aguas da Amazonia (Waters of the Amazon)” (1993-99) by the Chicago-based Third Coast Percussion that employs everything from a Thai gong and synthesizer to PVC pipes and glass marimba. The work is performed live by the percussion quartet alongside the extraordinary flutist, Constance Volk, who achieves an array of often otherworldly sounds.

Tharp is highly responsive to the sounds coming from the pit — the iterative, minimalist feel expected of Glass but also a distinctive Brazilian flavor that she carries into the movement, which is more sinuous, more urgent and emphatically rhythmic than in “Diabelli,” with some nifty slow-motion effects in the opening.

Overall, the work is darker and more mysterious, with dancers in black soft shoes and black shorts and tanks (or variations thereof) sometimes performing in shadowy silhouette. That said, “Slacktide” is a similarly scaled ensemble piece (12 dancers instead of 10) and the movement vocabulary largely mirrors that in “Diabelli.”

Tharp uses some of the same choreographic tricks, performers standing to the side reacting to the movement or two shoving to get ahead of another, and she oddly even pairs some of the same dancers together again.

« Previous post: I CARE IF YOU LISTEN: Third Coast Percussion’s “Standard Stoppages” Honors Two Decades of Innovative Music-Making

Next post: Chicago Tribune: Twyla Tharp Dance celebrates 60 years with something old, something new in stunning night at the Harris »