It's only fitting that the Pittsburgh Symphony Orchestra's Andres Cardenes would open the season that is to be his last as its concertmaster.

Last night's affair at Heinz Hall was somewhat surreal as a result. Here was Cardenes in his yearly conducting gig with the PSO welcoming patrons to the new season. (The orchestra postponed the previous week's season-opening concerts due to the G-20 summit).

The compelling program of lesser-known and blockbuster works was a direct result of years of his experimentation with the PSO's now defunct chamber orchestra series. And yet, it was hard to get too excited about the evening because it was the last time we will see Cardenes in this role. Unless he is invited back as a guest conductor, that is.

The gem of the night was a Pittsburgh Symphony premiere, Francis Poulenc's "Sinfonietta." Painted with such vivid colors and shifting quickly through many harmonies, the piece has a dreamlike ambiance. But Cardenes realized that a conductor must not get caught up in trying to enhance this by altering the tempos. Instead, he led the work with a precise beat that served almost as poles to a colorful tent, an apt analogy considering the circus-like raucousness of the finale.

The opening movement had pungent solos by trumpeter George Vosburgh and horn players William Caballero and Zachary Smith but also wonderfully sonorous playing by the strings. The third unleashed a resonant solo played just so by animated clarinetist Michael Rusinek (the more he moves in his seat, the more artistry he pours into his solos).

On first hearing, "Sinfonietta" swims around harmonically, but it has such a freshness and depth that it should be marked for a return to the Heinz Hall stage someday soon.

Cardenes pared the orchestra down to a chamber ensemble for Antonio Vivaldi's famous "The Four Seasons," but the energy didn't dissipate in the least. This time leading from the solo violin, he urged the players on to a compellingly aggressive performance of the work that depicts weather and people as the season's change.

Cardenes was in top form, flying through this music with bravado, but only when the music demanded it. His reverence for the music he plays, a hallmark of the Josef Gingold-trained musician, was always evident. Several principals had central roles: violinists Mark Huggins and Jennifer Ross, cellist David Primo and violist Tatjana Mead Chamis.

Cardenes' good friend and audience favorite, PSO principal cellist Anne Martindale Williams, took the stage in between these works to solo in Pyotr Ilyich Tchaikovsky's "Variations on a Rococo Theme." Williams played the work with her customary panache, not to mention that gorgeous tone she can pull out of her instrument's lower strings. The faster sections could have been cleaner, but her expressive playing captured the slower, lyrical variations well.

The program repeats at 8 p.m. today and 2:30 p.m. tomorrow.

Critics Andrew Druckenbrod and Scott Mervis talk about music on "The Beat," available exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.