Mozart did not compose much of the music performed in a concert entirely devoted to his work.
Strange, perhaps, given the occasion -- the opening concert of the Pittsburgh Symphony Orchestra's Mozart Festival. Even if you were a Mozart expert, Friday night's performance, led by Manfred Honeck, would have included music you'd never heard.
That was the case with at least one Mozart scholar at Heinz Hall: pianist and Harvard professor Robert Levin, who played an improvisation based on musical phrases submitted by the audience during intermission. He was taking a cue from Mozart, who would, as Mr. Levin put it, "shake the notes out of his sleeve" in coming up with cadenzas, decorations and fantasies on the spot.
Mr. Levin drew three slips of paper -- including two that quoted "Rigoletto" and "Ave verum corpus" -- and spun an improvisation in the classical style, roughly five minutes long. The improvisation had high-octane sections, or a waltz, or ponderous (and dare I say jazzy) playing. All of it was impressive and made for an engaging performance.
The fantasy had come after Mr. Levin's rendition of the Concerto No. 20 in D minor. In this piece, too, Mr. Levin offered a performance that was both unapologetically Mozartian and wholly new, with nimble, improvised cadenzas in the first and final movements, crushed decorations throughout, and a brisk tempo in the second movement. He also quietly accompanied the orchestra in non-solo material that pianists often forgo.
A few awkward notes stuck out, perhaps by the very nature of improvisation, and at times the balance with the orchestra was off, especially in the middle movement. But what the performance lacked in polish it made up for with a fresh and intimate experience: This concert will never exist in quite the same form. When Mr. Levin made a grand gesture and then started playfully dancing after his last cadenza, someone in the audience started clapping. Today's classical music world does not provide enough opportunities for concerts or training in improvisation, but Mr. Levin offered a compelling defense of the practice.
Following the improvisation was Mr. Levin's completion of Mozart's petite Horn Concerto No. 1, performed by Bill Caballero. The PSO principal horn player showed off a sensitive, soft tone throughout, letting a more blustery sound come through during a brief cadenza in the second movement.
The concert closed with Mozart's Symphony No. 41 ("Jupiter"). Mr. Honeck cultivated a beautiful, clean performance from the orchestra. Silky, ribbon-like melodies flowed from the first violins in the second movement, and the orchestra punched out the myriad themes of a fast, boisterous final movement. I wish that expressiveness had translated to the opening movement; the descending 32nd-note figure from second violins and violas wasn't quite skewered enough, and the speech-like character of the reference to "Un bacio di mano" didn't come through.
The orchestra began with a bright, unified performance of "Eine kleine Nachtmusik," with tightly hewn dynamics and quick tempos in the outside movements.
Concert repeats 8 tonight and 2:30 p.m. Sunday.
Elizabeth Bloom: email@example.com or 412-263-1750.