Not allowing Mahler to rest on his laurels

If there's danger lurking in this era of Mahler Utopia - in which the composer's symphonies are played constantly, with burgeoning confidence and to sold-out auditoriums - it's that we'll all be happy with the uniquely exhilarating towers of sound and leave it at that. Really, the Philadelphia Orchestra and the Philadelphia Singers Chorale needed only to show up for Thursday's Kimmel Center performance of Gustav Mahler's Symphony No. 2 ("Resurrection") to guarantee a cheering audience.

That's why the most important thing about the performance was that music director Christoph Eschenbach didn't count on that. No performance I've heard - at least in the first movement, which is packed with compelling ideas in heavy argument with each other - has been laid out in such a caring, smart interpretive grid. Repeating sequences of music never came out the same way twice. The score's more easily overlooked changes in volume were observed in ways that unleashed a dramatically new tint.

Looking at the big picture, you realized what a forward progression these nuances were creating, the sort that's sought by early-music interpreters to save baroque music from its sewing-machine sameness.

Apply this to Mahler, and one's ears go deeper into the score. The execution required and received playing of great sensitivity from the strings, though with a sound more like the Cleveland Orchestra's: Passagework hadn't the slightest flab, and the cleaner sonorities facilitated greater musical understanding.

All of that said, the most appropriately terrifying moments came when phrases weren't differentiated: Two-thirds through the first movement, the loud, relentless series of triplet rhythms backed the symphony into a corner with devastating impact, cunningly aided by a slowing of the tempo that gradually started before the score asked for it - the better to integrate it into the overall musical fabric. Thus, an effect that might have been a rerun of past performances took on a powerful new affect: It felt like quicksand.

Other movements each projected a highly individualistic sound world, as they should. Especially fine was "Urlicht," in which wind soloists were like sympathetic bedside visitors to the suffering text, sung by mezzo-soprano Yvonne Naef with luster and dignity. Verizon Hall lights were raised so listeners could follow the program's English translation.

The performance was recorded live, and I readily offer the most optimistic predictions for its outcome, with the exception of the choral finale. Yes, there were flubs. Its sprawling construction usually resists a cogent performance (the movement is the weakest of Mahler's finales) and did so here. Future performances could use some divine intervention. Gustav, are you listening? Are you busy at the moment?