Tomes are available annotating the importance of this recording. The musical and social impact of Miles Davis, his collaborative efforts with Gil Evans, and in particular their reinvention of George Gershwin's Porgy and Bess are indeed profound. However, the most efficient method of extricating the rhetoric and opening is to experience the recording.
Few other musical teams would have had the ability to remain true to the undiluted spirit and multifaceted nuance of this epic work. However, no other musical teams were Miles Davis and Gil Evans. It was Evans' intimate knowledge of the composition as well as the performer that allowed him to so definitively capture the essence of both.
The four dates needed to complete work on Porgy and Bess include contributions from several members of his most recent musical aggregate: Julian "Cannonball" Adderley (alto sax), Paul Chambers (bass), and Jimmy Cobb (drums). Although the focus and emphasis is squarely on Davis throughout, the contributions of the quartet on "Prayer (Oh Doctor Jesus)," "I Loves You, Porgy," and "There's a Boat That's Leaving Soon for New York" are immeasurable.
They provide a delicate balance in style and, under the direction of Evans, incorporate much of the same energy and intonation here as they did to their post-bop recordings.