Most of the time, a soloist subbing for an ailing musician enjoys a bit of a pass and even a boost from the audience. It's difficult enough to play complex classical music without an accelerated timetable.

But last night at Heinz Hall, Jorge Federico Osorio didn't need either. Tapped by the Pittsburgh Symphony Orchestra to step in for the ailing pianist Horacio Gutierrez (who himself had been subbing for an ill Rudolph Buchbinder), Osorio gave one of those, "where have you been all my life" performances under music director Manfred Honeck. It will never cease to amaze me just how unscientific classical music evaluation is -- and I practice it for a living. An orchestra really never knows for certain who will click with its audience, and with all the big names out there, there are always lesser-known tremendous talents such as Osorio waiting to debut.

Osorio is, however, known in musical circles for his Brahms, and he delivered in the composer's symphony-turned-concerto, the Piano Concerto No. 1. The Mexican pianist unveiled a luxurious tone capable of immeasurable variation. In fact, his strength was never submitting to an uncomplicated approach.

Brahms was conflicted in this work, which he began as a response to Beethoven's dominating symphonic output, and Osorio captured that with rich and layered approach, such as a measure of elegance in the furious sections to underlying power in the lyrical sections. He poured on weight only in certain key sections, and the result, along with Honeck's direction, was an emotional, up-and-down reading or a work that is exactly so.

As you likely know by now, Honeck's background is Austrian and Viennese, but he also has strong roots in the Czech Republic. His family emigrated from the region during the Napoleonic wars, and there is no doubt about that connection when you hear him conduct Dvorak. Dispensing with the score, his confidence spilled over to the orchestra in Dvorak's Symphony No. 8.

From wild, Bohemian trills in the horns, bird calls and peasant dances to wide vistas of sound, sophisticated phrasing and nostalgic touches, this was a reading for the ages. The first movement and finale were electric, but Honeck showed his understanding of the piece by accentuating the scope of emotion and dynamics in the expansive second movement.

The PSO soloists were brilliant, and the strings sound positively radiant in Honeck's new (or rather old-style) configuration in which the violins are split across the stage. But visiting concertmaster Ellen DePasquale, one of several who are auditioning for the spot Andres Cardenes will vacate after next season, led well and had a sonorous solo.

The program repeats at 8 tonight.