Rhapsody in Blue is a composition by George Gershwin which combines elements of classical music with jazz-influenced effects.

Rhapsody in Blue was commissioned by Paul Whiteman for a 1924 concert entitled "An Experiment in Modern Music," which took place in Aeolian Hall in New York City. The event has since become historic specifically because of its première of the Rhapsody in Blue.

Paul Whiteman's "orchestra" was a very popular dance band. Whiteman styled himself "The King of Jazz". (This appellation, applied to Whiteman's band of all-white musicians playing from written arrangements, would be questioned today, but in the 1920s the word jazz was used loosely to cover a broad range of contemporary popular music). Gilbert Seldes , in his book The Seven Lively Arts , was one of the first books to treat popular culture in a serious way, and "jazz" was starting to be seen as a significant American contribution to musical culture. Whiteman undertook to present what for the most part was an ordinary set of dance-band numbers in a concert hall under the trappings of high culture . Dance-band numbers were presented under headings such as "True Form of Jazz" and "Contrast: Legitimate Scoring vs. Jazzing." The reception was lukewarm until Rhapsody in Blue was played. It was performed by Whiteman's band with an added section of string players, and George Gershwin on piano (partially improvising his piano solo). It was an instant success. Whiteman adopted it as his band's theme song, and opened his radio programs with the slogan "Everything new but the Rhapsody in Blue".

Two audio recordings exist of Gershwin performing the piece with the Whiteman Orchestra, and a piano roll captured his performance in a piano-solo version. The Paul Whiteman Orchestra performs the piece in the 1930 film King of Jazz featuring Ferde Grofé on piano.

Rhapsody in Blue was orchestrated by Whiteman's arranger, Ferde Grofé, originally for the instrumental complement of Whiteman's band, then later for full symphony orchestra. Since the mid-20th century it has usually been performed by classical orchestras playing the expanded arrangement. In this form, it has become a staple of the concert repertoire. It is one of the pieces, like Dvorak's "New World" symphony, which has direct popular appeal while also being regarded respectfully by classical musicians. Classical commentator Ethan Mordden refers to Gershwin's sense of development and structure as "immature" but "not all that inferior to that of the average conservatory graduate." He characterizes the Rhapsody as "taut, incisive, expertly defined in what it is that had not been before."

In the 1990s, interest in the original arrangement has revived. Reconstructions of it have been recorded by Michael Tilson Thomas and the Los Angeles Philharmonic, and by Maurice Peress as part of a reconstruction of the entire 1924 concert.

Whiteman's clarinettist, Ross Gorman , showed Gershwin a virtuoso maneuver by which he could produce a smooth, unbroken multi-octave glissando. Such a glissando opens the Rhapsody in Blue. There seem to be few classically-trained clarinettists who can perform this correctly, and it is a weak spot in many recordings by symphony orchestras.

There is a story that about three weeks before the "Experiment in Modern Music" concert, Gershwin was listening to the radio and heard an advertisement for it, including that the concert would be premièring a new work by none other than himself, George Gershwin. So he hastily set about composing a piece, and in three weeks, Rhapsody in Blue was born. However, due to the lack of time, Gershwin did not write out the piano part, only the band parts. As a result, he improvised some of what he was playing. He didn't write out the piano part until after the performance. So we really don't know what the original Rhapsody really sounded like.

As of 2004, the copyright on Rhapsody in Blue expires in 2007 in the European Union and between 2019 and 2027 in the United States of America.

Brian Wilson was reportedly heavily influenced by this music, and the SMiLE project can almost be thought as a direct offshoot of the concept, with its three movements and unmistakably American song structures. During the film "Beautiful Dreamer: Brian Wilson and the Story of SMiLE" Brian Wilson is shown playing the introduction of Rhapsody in Blue on the piano, then directly segueing into the SMiLE song "Heroes and Villians"