There is an extraordinary shift taking place at the Pittsburgh Ballet Theatre. Once the bastion of family-style story ballets and entertaining works that generally played it safe, this local company is stretching its wings and catching up with the dance world. Judging by an enthusiastic reception on Friday night at the Benedum Center, Pittsburgh audiences are willing to follow.

Not that PBT is abandoning its base -- "Alice in Wonderland" closes out the season in April, albeit with Derek Deane's updated production -- but this was a program of exciting choreography melded with top-notch dancing.

Choreographers Twyla Tharp and Dwight Rhoden went head to head in an evening of dance that was, at times, relentlessly percussive. But then the performers remained collectively in step with the theme -- Maribel Modrono never looked better than in Tharp's playfully feminist "Junk" duet with Christopher Budzynski, set to Donald Knack's appropriately clanking junkyard score -- and went beyond expectations.

Tharp's "Octet" opened the program to Edgar Meyer's country and jazz- inflected percussive score, but Tharp elected to go against the grain with a classically oriented vocabulary in the Balanchine mold, and PBT artistic director Terrence Orr provided a leggy cast well-suited to the style. They were almost pristine, floating above Meyer's music in a nouveau "Square Dance." In an odd way, it was similar to Balanchine's 1957 work, where he put an Americana accent to Vivaldi and Corelli using fast footwork and high extensions. One might have expected a Tharpian twinge or two to enhance the strict balletic vocabulary, but the choreographer and PBT dancers played it close to the vest.

The fact that both of these works laid a heavy emphasis on percussion (the original programming choice, Tharp's "In the Upper Room," had an ethereal but decidedly minimalist Philip Glass accompaniment), made it more difficult for "Carmina Burana" to rise above what had gone before it.

Carl Orff's score gets its propulsion from thickly constructed chords that mostly proceed in a piston-like fashion. It is at its best when it marshals its forces, in this instance the PBT dancers and orchestra (with conductor Charles Barker authoritatively at the helm) and The Mendelssohn Choir (beautifully rehearsed by Betsy Burleigh to take advantage of the dynamic contrasts). Of the vocal soloists, baritone Brian Keith Johnson displayed a rich sonority and tenor Dillan McCartney a sweet clarity. Soprano Jennifer Saunders, however, seemed forced in the high passages.

Rhoden's grand vision has always had a sweep to it, and in "Carmina Burana" he was able to trumpet the excesses of gluttony, debauchery and eroticism. The stage teemed with his always inventive choreography -- sometimes too much so -- but the dancers were always compelling.

Julia Erickson presided over this "Carmina" like a glamorous sorceress, with Robert Moore firmly in her grasp. In the opening she was clad in a giant red skirt, cloaking her minions in the passions that would unfold. She navigated the movable barbed-wire fence at the back and blithely sat on a swing dripping flowers.

The intensity never let up, both in the score and the choreography. And at the end, the pulsating rhythms had latched onto the heartbeat of an appreciative audience.