rock and roll is essentially roots country and blues played at a faster upbeat tempo. so if you really want to start at the origins, you'd go with the old blues masters like robert johnson, leadbelly, sun house, etc...and the country dudes like hank willaims, woody gunthrie, johnny cash, and loretta lynn. but if your wanting to start with when rock became rock, you start with chuck berry, he's the man responsible for it all. you'd also then go to ray charles, little richard, etc....AND then you get to the dudes like elvis and buddy holly who made rock music acceptable for white people and pushed it into the mainstream. then you get guys like bob dylan. then theres the british invasion with the rolling stones, the beatles, the kinks, the animals, etc....
