Maestro Manfred Honeck is crafting the Pittsburgh Symphony Orchestra into a graceful ensemble capable of the subtlest of Viennese nuances. But last night at Heinz Hall, the PSO's principal guest conductor Leonard Slatkin reminded us that it's an American ensemble first and foremost.

Bright, bold and brilliant sounds burst out in an evening of works by American composers Aaron Copland, Samuel Barber and John Williams, the latter's piece a newish horn concerto performed by the orchestra's extraordinary principal William Caballero.

What a fantastic pairing it is that the symphony has Honeck and Slatkin as artistic forces. If Honeck had an eighth of the ridiculous hype poured on Gustavo Dudamel, newly arrived at the Los Angeles Philharmonic, the country would be green with envy over this duo (not that I don't want Dudamel to succeed, but come on, PBS "Great Performances" specials already!?).

At the helm of the PSO is an inspired conductor in Honeck, steeped in the European canon with connections galore on the continent. Complementing him is the esteemed doyen of American music in Slatkin, an eloquent advocate with the microphone or stick in his hand.

Take last night at a packed Heinz Hall. Getting a head start on celebrating the Barber centennial (1910-81), Slatkin of course offered the famous Adagio for Strings. But he gave the work, which was originally the second movement of his string quartet, similar context by making it the "middle movement" of a patchwork symphony consisting of standalone works: the Overture to "The School for Scandal" as the opening movement, then the Adagio and then "Medea's Meditation" and "Dance of Vengeance" as the final two movements.

Then Slatkin sculpted the Adagio for Strings with more shape than I've ever heard. The climax had a twinge of anxiety to it and the return of the famous theme after this arrived with extra ritardando, wonderfully accentuating the denouement quality of the end. So many conductors would just toss off a piece like Adagio that has lost luster due to its pop culture connections and popularity, but not Slatkin. Numerous individual musicians excelled with solos throughout the entire Barber set.

Given the fan that I am of Caballero's exquisite playing over the years, Williams' Concerto for Horn and Orchestra was a letdown. I prefer Williams when he imitates Romantic composers in his film music more than when he imitates the post-moderns as he seemed to in this quiet, meandering score. I could excuse the noncommittal stylistic nature of the work, but not when, as a concerto, it should at the least show off the French horn. Instead, Caballero started playing "distant" and really never comes much closer.

There's a good deal of difficult playing in the part, which Caballero didn't blink at, and third movement brings out more of his rich timbre, but the piece was too understated. Only the last movement, a haunting Nocturne with shimmering string writing, had discernible and compelling musicality to it. Williams might want to consider following Barber here and putting it out on its own.

The concert opened with Copland's "El Salon Mexico" and closed with Four Dance Episodes from his "Rodeo," including the rousing Hoedown.

Not a waltz this time.

Program repeats tomorrow at 2:30 p.m.

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