Gershwin's set of variations on "I Got Rhythm" was his final concert piece, written for a demanding 1934 tour - 28 concerts in 28 cities in 28 days. The Variations were the only new music on the bill, and even these looked back to a hit number from Girl Crazy (1930). Ethel Merman had made her Broadway debut in the show, and her rendition of "I Got Rhythm" helped seal Girl Crazy's success and the song's fame.

Gershwin wrote the Variations in December 1933 and January 1934 while he was working on Porgy and Bess. The original version of the Variations was conceived for the tour's band, the 35-member Leo Reisman Orchestra. Gershwin was the soloist for the work's premiere at the tour's first stop, in Boston on January 14, 1934. William C. Schoenfeld reworked Gershwin's original for large orchestra when the work was published in 1953.

On his radio show Music by Gershwin, the composer explained that the work was in seven distinct parts - an introduction, the melody, four variations, and a finale. He continued, "After the introduction by the orchestra [beginning with a solo clarinet], the piano plays the theme rather simply. The first variation is a very complicated rhythmic pattern played by the piano while the orchestra takes the theme. The next variation is in waltz time [slow, with sighing violins and the piano marking the rhythm]. The third [beginning with chinoiserie from the xylophone and cymbals] is a Chinese variation in which I imitate Chinese flutes played out of tune…. Next the piano plays the rhythmic variation [largely reimagined by Schoenfeld as a jazzy, clarinet-led interlude] in which the left hand plays the melody and the right plays it straight, on the theory that you shouldn't let one hand know what the other is doing. Then comes the finale." It's a riotous ending to Porgy and Bess' lighthearted counterpart, a crowd-pleaser rather than any grand summation of Gershwin's art as a concert-hall composer.

- John Mangum is the Philharmonic's Program Designer/Annotator.