There’s a Boat Dat’s Leavin’ Soon for New York/It Ain’t Necessarily So/Summertime/I Got Plenty o' Nuttin’ is a song from the American opera Porgy and Bess, composed in 1935 by George Gershwin (1898–1937), to a libretto by DuBose Heyward and his brother Ira Gershwin, after Heyward’s novel Porgy – a story about the love between the crippled negro beggar Porgy and the girl Bess in the city of Charleston in South Carolina. The première – not a huge success – took place on 10 October 1935 in New York.

With his opera, Gershwin wanted to gain recognition as a composer of classical music. Incidentally he demanded that all parts were sung by black performers; only a few unimportant parts, without sung lyrics, were allowed to be performed by white actors. This rule still applies: Gershwin has stated in the terms of his will that only black people were allowed stage the opera.

Porgy & Bess has become popular only after Gershwin’s death. In 1959 a wonderful film was made; the soundtrack won a Grammy Award. The work is not very often performed, possibly because of the difficulty of finding a whole cast of black opera singers. However, various pieces from the opera are still regularly performed in numerous arrangements.