Even today Gershwin's music exposes the gaps between European and American musical sensibilities and the ambivalence in our musical culture. Two years ago in Vienna I heard the orchestra of the Metropolitan Opera, which many American critics have hailed as the finest orchestra in this country, perform Wagner's Rienzi Overture, Bartók's Miraculous Mandarin, Strauss's Don Quixote, and, almost as an encore, Gershwin's An American in Paris -- a difficult program, chosen to show off the orchestra's technical prowess and stylistic range. The audience sat on its hands after the first three works, bursting into an ovation only after the Gershwin. In the papers the next day Viennese critics hauled out their usual clichés about American orchestras (too loud, too slick, too impersonal) and saved their praise for the Gershwin -- the only kind of music we Americans, apparently, can really play well.

We Americans, however, have yet to make up our minds about Gershwin. Even though he is the one twentieth-century American composer whose music is played all the time and everywhere, Gershwin is an isolated and inimitable figure -- the only popular composer of this century whose works have made a lasting dent in the granitic façade of the classical canon. But this achievement is either pushed aside as a kind of embarrassment or described in terms of mindless self-congratulation, with George -- the self-made millionaire, the Jewish mother's prize, the sex symbol, the man of the people -- playing out every cliché of the American Dream. Jazz historians barely mention the composer of "I Got Rhythm," whose harmonic progression supports nearly as much jazz improvisation as the blues; and most accounts of twentieth-century classical music treat Gershwin as a speck compared with giants like Stravinsky, Ravel, and, more recently, Ives. At the same time, though, Gershwin concerts invariably sell out; the all-Gershwin concert by the San Francisco Symphony and Michael Tilson Thomas that opens the Carnegie Hall season this fall is the hottest ticket in New York. Gershwin's reputation in this country rises and falls with shifts in the balance of power and prestige between popular and classical music. When pop rules, as it does today, Gershwin is the father of us all. When pop palls, and it may yet again, he is a blot on the musical landscape.

Gershwin will remain unique not because he mixed classical and popular -- many other composers have done that -- but because of the way he combined the two. His classical pieces could have been written only by a composer whose primary form of expression was the thirty-two-bar popular song; his songs owe their distinctive character to his early study of and abiding love for the classics. All his classical pieces contain tunes that could have appeared in shows, but they also helped him to enrich the harmonic sophistication and expressive warmth of his popular tunes. These contradictory styles and forms distanced Gershwin from other songwriters and classical composers, and they continue to stump most critics of his music.