Well-laid plans for any new music ensemble probably don't exist - it's a side effect of embracing the unknown - which means the Orchestra 2001's opening-season concert on Friday was extremely promising in ways that weren't superficially apparent amid peripheral problems.

In a program titled "Body Music" (embracing dance and more elemental functions), the group introduced new artistic director Jayce Ogren, made its debut at the Center for Architecture and Design on Arch Street, played music involving tricky electronics, and held a celebratory reception. That's a lot.

But amid noisy air-conditioning, creaky floors, and iffy sightlines, the crucial aspect of the concert was the strongest: Ogren conjured strong, solid playing with bursts of heat.

He introduced each piece invitingly with explanations that didn't spoil your own discovery. John Adam's Son of Chamber Symphony, for one, combines the skipping rhythm of Beethoven's Symphony No. 7 with modern funk. Knowing that made you appreciate how the composer had fused those elements to create his own distinctive idea with no debts to the antecedents.

The playfully dense first movement has many pockets of music filled with ideas that intriguingly seem upside down or backward, all packed into the smallest possible module. The orchestra was admirably accurate but didn't fully apprehend the music until the final movement. Then the performance cooked. Better to leave listeners remembering what the piece can be rather than wondering what it was.

In Sebastian Currier's Bodymusic in the second half, the 16 movements explore a body sound or state of mind, augmented with sounds often prerecorded from real life, spatially rendered by speakers in each corner of the room. Movements were brief and descriptive, like micro tone poems. The "Humiliation" movement had a muted trumpet interacting with recorded crowd laughter. "Very Quiet" shimmered with instrumental color. "Gossip" had busy woodwinds and recorded whispering. Inward-looking movements, however, felt opaque.

Ogren was keen to show what's possible in electronic/orchestral effects. But all 16 of these not-always-well-sequenced movements weren't necessary. The audience grew restless. Younger listeners departed. A pity, because the concert ended with Joan Tower's Petroushskates, a reimagining of Stravinsky's Petroushka with wonderful pianism from Charles Abramovic.