As described in Wikipedia:
Rhapsody in Blue is a 1924 musical composition by the American composer George Gershwin for solo piano and jazz band, which combines elements of classical music with jazz-influenced effects.
The composition was commissioned by the bandleader Paul Whiteman. It was orchestrated by Ferde Grofé several times, including the original 1924 scoring, the 1926 “theater orchestra” setting, and the 1942 symphony orchestra scoring, though completed earlier. The piece received its premiere in the concert, An Experiment in Modern Music, which was held on February 12, 1924, in Aeolian Hall, New York City, by Whiteman and his band with Gershwin playing the piano.