NEW YORK — What promised to be a mid-to-lightweight gala Wednesday when the Philadelphia Orchestra opened the Carnegie Hall season turned out to be a concert that could well achieve infamy. Pick an adjective — outrageous, extravagant, tasteless, tedious, revelatory, disrespectful — and any one of them applies.

The Philadelphia Orchestra was in perfectly fine form, dishing out sassy solos in the opening of Gershwin's Rhapsody in Blue. Music director Yannick Nézet-Séguin was in hyper-alert Bernstein mode conducting Symphonic Dances from West Side Story — having also spent the day in New York rehearsing his singers for Oct. 12-15 performances of the complete score with a cast featuring the glamorous Isabel Leonard.

The wild card was pianist Lang Lang's role in Rhapsody in Blue — the one part of the Carnegie program that won't be repeated at the Thursday opening of the Philadelphia Orchestra's season at the Kimmel Center.

Having suffered a left-arm injury, Lang Lang employed a two-piano version of Rhapsody in Blue and invited jazz pianist Chick Corea to play the performance with him. Pinch-hitting for his bad arm, pianist Maxim Lando sat at Lang Lang's side, filling in. Some called it "the five-handed Rhapsody in Blue" because Lang Lang was reportedly using his bad arm here and there.

You knew you were in for something different when Corea began improvising at his first entrance, decorating melodies with his own kind of ornaments and bolstering the tunes with saturated Debussy-style harmonies — much of it, including allusions to the song "The Man I Love," quite beautiful. Soon, competitiveness set in.

Lang Lang and Lando didn't improvise in the same way as much as they gave all manner of alternative readings to Gershwin's tunes and aggressively fussed about with the rhythms, often in ways that showed the composer was right the first time. The interplay was sometimes electric when Corea picked up on what Lang Lang was doing and went his own way.

But after a while, the performance was like a series of improvisations for the pianists with occasional orchestral interludes. Nézet-Séguin sometimes seemed to be grooving to the more interesting rhythms they played, but mostly seemed like a patient parent waiting for his kids to finish acting out. The fun, games, and self-indulgence continued even into the final moments when Lang Lang held up the final resolution for grander effect. Hopes for anything cogent had long ago been dashed.

Most of the extremely well-heeled audience stood and cheered. Those who did not stand looked appalled. My reaction: I loved and disliked it in equal parts, and after a while, the piece simply went on too long. Difference of opinion will no doubt continue: The concert was broadcast live on WQXR radio and will be available on demand in the coming days.

And the rest? Bernstein's Symphonic Suite from On the Waterfront made a strong impression — maybe too strong as the orchestra forced its sound, except on moments of Edward Hopperesque starkness. The West Side Story dances were a positive harbinger of what's to come: The orchestra's luxurious sound could easily become obtrusive in this intimate adaptation of Romeo and Juliet, but the sonorities were rendered with great dramatic precision that heightens the score's considerable impact.

Philadelphia Orchestra Opening Night

With pianists Harmony Zhu and Emanuel Ax. 

7 p.m. Thursday at the Kimmel Center, Broad and Spruce Streets.

Tickets: $50-$175. Information: 215-893-1999 or