The famous stage Director Rouben Mamoulian once said of George Gershwin:
I've heard many pianists and composers play for informal gatherings, but I know of not one who did it with such genuine delight and verve. George at the piano was George happy. He would draw a lovely melody out of the key-board like a golden thread, then he would play with it and juggle it, twist it and toss it around mischievously, weave it into unexpected, intricate patterns, tie it in knots and untie it and knit it into a cascade of ever-changing rhythms and counter-points…He could play ‘I Got Rhythm’ for the thousandth time, yet do it with such freshness and exuberance as if he had written it the night before.
It was for a concert tour in 1934 that Gershwin immortalized some of his informal extemporizations as the Variations on "I Got Rhythm," the hit song from his 1930 Broadway show Girl Crazy. The tour was a series of one-night stands with the thirty- piece Leo Reisman Orchestra, conducted by Charles Previn, that began at Boston's Symphony Hall on January 14, wound through Toronto, Omaha, Richmond and two-dozen other cities, and ended, after 12,000 miles, at Brooklyn's Academy of Music on February 10th. On each concert, Gershwin conducted An American in Paris, was soloist in the Concerto in F and the Rhapsody in Blue, and accompanied tenor James Melton in a selection of his songs. The "I Got Rhythm" Variations, written expressly for the tour, gives some indication of the breadth and imagination that Gershwin must have displayed in his improvisations - hot jazz, mock Orientalism, coy waltz, virtuoso bravura and grand symphonism all find a place here. Most of the composition was done in December 1933 in Palm Beach; the orchestration, which Gershwin did himself, as he bragged to his friends, was completed on January 6, 1934 in New York. The "I Got Rhythm" Variations was the last concert work that he wrote.