Beethoven's practicality-defying Symphony No. 9 rarely sits comfortably on orchestral programs: Not long enough to be heard by itself, the piece is so idiosyncratically monumental that finding suitable pairings is tough.

A bookend approach with Beethoven's Symphony No. 1 is the easy way out. On Thursday, Yannick Nézet-Séguin opened the first subscription concert of his second Philadelphia Orchestra season determined not to make the Westminster Choir come all the way from Princeton just for Beethoven's final movement. Besides the composer's cantata Calm Sea and Prosperous Voyage, he went out on a limb with a newly orchestrated version of Nico Muhly's Bright Mass and Canons.

The deeply fashionable Muhly, whose Dark Sisters was a significant Opera Philadelphia hit, is as prolific as his mentor Philip Glass, and not everything has to be major. Bright Mass is a "missa brevis" with soothing, direct, Anglican-flavored choral writing. Its contemplative manner invites you just to sit with the words and see how they speak to you.

That might happen more readily in venues more intimate than Verizon Hall. The new orchestration seems to belong to a different piece - late-period Stravinsky. Originally a minor work, it's now a minor work that's bigger. But Muhly pieces are like buses: If you don't enjoy one, another arrives soon, more to your liking.

On to Beethoven: Nézet-Séguin's macro view of the Symphony No. 9 had inconsistencies: The first two movements had breakneck speeds suggested by Beethoven's metronome markings. The slow movement was quite slow. The final choral movement was all speeds.

Each individual movement, though, was as compelling as can be - an achievement in a symphony with hidden traps that come with being unprecedented in its own time, but written by a composer whose deafness kept him from testing it out.

The first two movements are huge constructions built from humble two- and three-note motifs, the profound implications of which can be lost at fast tempos. On Thursday, opening moments bristled with quiet tension, though meaning occasionally drifted amid the high-traffic second movement.

The third movement was as sublime as you could want, plus having a strong through line - a preview of the minor miracle wrought in the finale. Most "Ode to Joy" performances concede to the music's heterogeneity as the piece jumps from vocal soloists to chorus to Turkish street band. Nézet-Séguin welded everything together with tight pacing and sheer interpretive will.

Besides nailing Beethoven's awkward vocal writing, the Westminster Symphonic Choir projected meaning with more specificity than I've ever heard. Indeed, the choir was singing in sentences.

Soloists (including Mihoko Fujimura, Christian Elsner, and Shenyang) were all good, though star soprano Christine Brewer canceled due to allergies. Twyla Robinson was a worthy replacement, but Brewer's Wagnerian magnitude had a better chance of taming Beethoven's vocal lines.

Additional performances: 8 p.m. Saturday and 2 p.m. Sunday at the Kimmel Center. Information: 215-893-1999