George Gershwin himself may not have agreed, but some believe his greatest work was "Porgy and Bess." Certainly the jazz community concurs. The familiar music has been recorded again and again by jazz greats who revel in the folk/blues/jazz themes that power the score.
Great example: Miles Davis, and it's amazing that he didn't think to do it before 1958. Long before that, he had stopped playing his horn and started, in effect, singing through it. His rich tones and moody phrasing are perfect for a score meant for voices.
Gil Evans deserves plenty of the credit for this record. He gathered a large, all-star band (Julian Adderly, Paul Chambers, Philly Joe Jones) and led it through his Ellington-esque arrangement, which beautifully backs Davis' lone trumpet and fluegelhorn. The arrangement itself is worth the price of this album.
Columbia has included the album in its Jazz Masterpieces series on CD (CK 40647) and cassette (CJT 40647). Some version of it belongs in every serious jazz collection.