Dutoit conducts a charging "Oedipus Rex"

The pulsing, insistent triplet figure shared by the cellos, double basses, and timpani at the end of Stravinsky's

Oedipus Rex

has a way of following you out of the hall, down the street, and hounding you.

It's a quiet way of ending a horrific piece, yet the triplets won't let go - the three beats like drops of life leaving Oedipus and the bodies of his parents.

It is the job of an orchestra, in addition to everything else, to take risks and lead public taste. That's easy to forget in an age when the act of curating programming has so closely elided with channeling the customer's wishes. In these conservative times, Oedipus Rex counts as risk.

I doubt that anyone was clamoring for the Philadelphia Orchestra's current performances of the piece, and it was a pretty thin crowd that showed up Friday afternoon. But we have to thank Charles Dutoit for its appearance, and if the 50-minute opera-oratorio's musical language can be austere, there's nothing to fear: It can also be sensuous and mysterious, and tantalizingly ambiguous.

Augmented by the solid men of the Philadelphia Singers Chorale, narrator, and five vocal soloists, Dutoit led a charged performance of the piece, last done here in 1992, also with Dutoit, and only once before, in its U.S. premiere by this orchestra, in 1931.

Dutoit, always the deft programmer, paired it with the score to Stravinsky's ballet Apollon musagète - an excellently understated foil to Oedipus Rex. Apollon musagète exists within a narrow emotional range, and here, with strings alone, it came across as a cool score warmly played.

Oedipus Rex embraces a panoply of emotion, much of it embodied in the title role, sung magnificently by tenor Paul Groves. When confessing to killing the man he believes to be a stranger, Groves skillfully marred his sound - half speaking, half singing. The rest of the cast - mezzo Petra Lang (Jocasta), bass-baritone Robert Gierlach (Creon/Messenger), baritone David Wilson-Johnson (Tiresias), tenor Matthew Plenk (Shepherd), and David Howey (Narrator) - were uniformly fine, and sometimes a great deal more.

Stravinsky's orchestra is a full dramatic partner in the piece, a role Dutoit and the ensemble exploited with tenderness, outrage, and, most notably, in passages where mood of the orchestral writing and the text stood in defiance of each other, horribly and wonderfully.

Additional performance: