Musicologist Susan McClary writes about how the blues was adopted by white British middle class men in the early 1960s, e.g., by Eric Clapton, and turned into rock (from Conventional Wisdom: The Content of Musical Form, pp. 58-59):
“Thus the priorities of the genre [i.e., the genre of blues music] changed when it was adopted by British rockers — as they had, for that matter, when the blues had passed from Bessie Smith to Robert Johnson. That the principal interests of the British differed from those of the African American musicians they initially idolized became clear when musicians and critics alike announced that they were ready to leave their black mentors behind and move forward into art rock. As Motown historian Dave Morse complained in 1971: ‘Black musicians are now implicitly regarded as precursors who, having taught the white men all they know, must gradually recede into the distance’ ….
“When middle-class kids and British art students ‘universalized’ blues by making it the vehicle for their own alienation, many black musicians chose to develop other modes of expression. For some of them, in any case, the blues had come to recall times of rural poverty and victimization — the genealogy sedimented into the blues had moved to the foreground for them, drowning out other registers of meaning. Thus it is no coincidence that rap musicians have worked to construct a different heritage, tracing their roots through sampling and quotation back not to the blues per se but to James Brown and soul — a genre of black music that emerged during the decade when white rockers arrogated the blues unto themselves. For African Americans the blues was always just one particular manifestation of a number of deeper elements that live on in other genres. It was never a fetish, but simply a vehicle for expression. When historical conditions changed, when it became reified, it could be left behind.”
I read this as a healthy reminder that the genre of rock is not somehow universal — and therefore rock can not become the be-all and end-all of liturgical music; indeed, no musical genre can serve as some kind of a universal liturgical expression.