The Pittsburgh New Music Ensemble is an ambitious group, but Friday night, so was the music it played.

Much of the best contemporary music of the past half-century is in the chamber realm. With orchestras, and opera companies to a lesser degree, sticking to a canon, contemporary composers simply found more opportunities with smaller forces. In many respects, the development of Western art music has come more in solo works, songs, trios, quartets and "Pierrot Lunaire"-sized chamber ensembles.

Composers never abandoned the desire to orchestrate symphonically; they just started squeezing more notes into fewer parts. The pieces on the PMNE program at City Theatre on the South Side were perfect examples. David Stock's "Into the Whirlwind," which opened the concert, was scored for flute (Lindsey Goodman), cello (Kathryn Bates) and percussion (David Skidmore). A chamber work, yes, but each player, especially percussionist Skidmore, played like at least two musicians.

The effect here and throughout was of music bursting at the seams, reaching for more rather than the deflating feeling we often get from much under-performing contemporary orchestral music. Actually, Stock's piece eventually got too caught up in this, ranging too far afield in multiple techniques and shifts. At first it appeared to be a dialogue between two stylistically competing groups, one supported by the toms and the other by the vibraphone. "Into the Whirlwind" eventually lost this structure and became too wide ranging. There were moments of beauty, though, especially in the gentle melody shared by flute and cello midway through.

Pierre Jalbert's "Visual Abstract," for all seven PNME instrumentalists, was a virtual symphony, with lush strains, layers and contrasts. Conducted by Kevin Noe, the piece continually churned with propulsive and vibrant music, again seeming to expand out beyond its actual orchestration. Paul Schoenfield's Trio for clarinet, violin and piano could have been mistaken for a larger klezmer band. Clarinetist Kevin Schempf wailed with passion in the work's sprint through the various klez landscapes. So, too, was "Buzz" an infectious work for violin, clarinet, cello and piano by James Matheson. It was an amped-up tribute to Rimsky-Korsakov's "The Flight of the Bumble Bee," and its first few notes themselves were turned into a persistent buzzing bee. Pianist Daniel Spiegle was especially impressive playfully articulating it.

Mathew Rosenblum's "Under the Rainbow" didn't hint at larger performing forces but simply included them, in the form of pre-recorded tracks.

The work follows a solo flute through a journey of sorts, ironically accompanied by club music and funny quips of well-known cartoon figures and movie characters, including from "The Wizard of Oz."

The latter is the obscured underpinning of the piece, brought distinctly, and perhaps in a slightly kinky manner, to the fore this time by flutist Goodman's dressing like Dorothy -- complete with ponytails, blue dress, red shoes and Toto. At first this threatened to put too much literal focus onto the abstract piece, which she played very well, but soon it became apparent Goodman was on to something. Bringing out Dorothy, she focused more on the symbolic role of innocence as the flute/protagonist travels through the piece, especially when it took stops at a sleazy lounge. Lighting by Andrew David Ostrowski also helped to affect this.

Having now heard "Under the Rainbow" several times, the flute line is now emerging from all the recorded, funny "accompaniment" for me. It's a lovely little melody, though a little melancholy, and in a sense the work is a modern version of a flute sonata.

The concert also saw the return of Kieren MacMillan's "Voices Aside," a funny, improvised work that finds five performers pretending to be the audience, complete with their wandering thoughts.

The final concerts of the Pittsburgh New Music Ensemble season are 8 p.m. Friday and Saturday at City Theatre on the South Side.