From Wikipedia: 
Porgy and Bess is a studio album by jazz musician Miles Davis, released in March 1959 on Columbia Records. The album features arrangements by Davis and collaborator Gil Evans from George Gershwin's 1935 opera of the same name. The album was recorded in four sessions on July 22, July 29, August 4, and August 18, 1958, at Columbia's 30th Street Studio in New York City. It is the second collaboration between Davis and Evans and has garnered much critical acclaim since its release, being acknowledged by some music critics as the best of their collaborations. Jazz critics have regarded the album as historically important.