There was an interesting programme about the origins of American-African line-out singing on telly a few weeks ago. Line-out is where the lead singer in a church choir sings the main line of the song, and then the chorus sings it out after him or her. The documentary makers took an all-white UK church choir (in fact, if memory serves me, they came from a little church in Scotland) over to the USA. There they sang line-out in the usual way, which it was believed that the original settlers had done during their services and which it was felt that Africans, then slaves and stuck at the back of church pews while being Christianized, would have heard and copied. The watching black singers listened with instant recognition of their own delivery, sung by an all-white group. Black gospel line-out was then sung, with this time the Brits amazed at how the chords and cadences synchronized with their own.
The premise of the film was to try to explain where black Gospel had come from, and it seemed to demonstrate its British origins pretty well. So Elvis's Gospel may have had its basis in black American Gospel choirs, but they in turn had based their way of singing on British choristers settling in the New World.
It'd be fairly reasonable to expect that some African slaves would bring tribal drumming skills to America and the Caribbean, even if this was frowned upon by their owners and the Church. There are strong indications that the drumming was toned down in order to be accepted by the whites as less 'savage', and probably that's why slaves began eventually to incorporate non-African instruments into their repertoire, along with traditional clapping, whistles, calabash 'maracas', etc. In order to be allowed to play at all, they had to learn to incorporate their rhythms into something that white folks found acceptable as entertainment.