American nowadays scene rips off->
Gothemburg 90´s scene rips off->
NWOBHM 80´s rips off->
early punk / 70´s progressive rock rips off ->
60´s rock n´roll rips off->
40´s Rhythm and blues rips off ->
African American culture... well before that I don´t know... Disco maybe?
Bit of a problem with this.
Progressive as we know it was largely born from two things - the first is Sgt. Pepper's Lonely Hearts Club Band by the Beatles and the second is the early work of Frank Zappa. Sgt. Pepper's Lonely Hearts Club Band was light years past anything that had happened before that in rock music, in terms of everything from production to songwriting to thematic grandeur, and to say that it ripped off 40s R&B is like saying that the inventor of sandwiches ripped off the inventor of sliced bread. Frank Zappa came from the typical rock background, one could say, but he was also heavily influenced by things ranging from the jazz at the time, which was becoming more complex with the growth of bebop, to modern composers like Varese. Zappa threw in so many new elements to the mix that there's simply no fucking way you could throw it back to R&B. Other bands like Pink Floyd, 1-2-3, and Genesis would be part of this movement and keep adding more complexity and intricacy to it, giving it a whole new depth - it is easy to argue the case that Elvis made money making black music for white people, and a lot of sixties rock just took that same step farther forward ( *cough* Rolling Stones *cough* ), but prog brought in so many other elements, including but not limited to jazz and classical, that pointing to its birthplace as R&B leaves out at least half of the picture.
Also, it seems hard to make the case that Scandinavian death metal would be near where it turned out to be if it were not for thrash metal, and the Florida death scene appears to be of significance as well. Now, yes, scene kids might like to water down Scandinavian metal and call it exTr33m, d00dz, but Morbid Angel, Death, Cannibal Corpse, Suffocation, Testament, Cynic, Megadeth, and other such bands seem to have thrown enough new stuff into the mix to make the American scene not look like an ignorant bunch of copycats.
Jeff