Soul music was also, indirectly, helped by rock music, precisely because rock music made white pop music sound so obsolete. Rock music buried white pop music but did not quite offer an alternative. On the other hand, rock music legitimized black pop music (rock music was basically a white version of rhythm'n'blues), and black pop music did offer an anternative to the Italian crooners and the likes.

    As the civil rights movement staged bigger and bigger demonstrations and increased African-American pride, soul music became more than party music for young blacks: it became a rallying flag for the black nationalist movement. While never truly political in nature, soul music's ascent in the pop charts came to represent one of the first (and most visible) successes of the civil-rights movement.

    Soul music was born thanks to the innovations of a generation of post-war musicians who, essentially, turned gospel music into a secular form of art.

    Soul music retained its vocals-driven image, typical of all pop music, but, like so much pop music, its hits became increasingly dependent on the skills of the arrangers and producers. In other words, soul music mutated transparently from a vocal style into a sound style.

    This mutation took place mainly in four places: New York, Memphis, Detroit, Philadelphia. And it corresponded with four independent labels, respectively: Atlantic (founded in 1947 by white songwriter Ahmet Ertegun), Stax (founded in 1959 by white country fiddler Jim Stewart), Tamla Motown (founded in 1959 by black enterpreneur Berry Gordy), and, much later, International (founded in 1971 by Kenny Gamble and Leon Huff).

    The sound of Atlantic was largely the invention of producer (and former critic) Jerry Wexler, hired in 1953. The peak of Atlantic's reign on soul music came when (1967) Wexler started working with arranger Arif Mardin and engineer Tom Dowd.

    The sound Of Stax, an elegant hybrid of rhythm'n'blues and country'n'western with simple arrangements and sober rhythms, was largely the sound of its session musicians (and their first producer, Chips Moman). The Mar-Kays' instrumental hit version of Chips Moman's Last Night (1961) pretty much set the standard for all subsequent Stax productions: punchy horns section (two trumpets and two saxophones) and powerful rhythm section (groovy organ, staccato guitar, bass and drums). The band's guitarist, Steve Cropper, one of the most original guitarists since Lowman Pauling, whose stinging riffs bridged country and blues, joined saxophonist and keyboardist Booker Jones and drummer Al Jackson to form Booker T. & The MGs, that released the similar instrumental shuffle Green Onion (1962), while trumpet player Wayne Jackson formed the Memphis Horns. These remained the house bands for all Stax musicians.