Dec 6, 1965 the Beatles released Rubber Soul. It was not a Rock 'n' Roll album. It was Rock.

May 30, 1966 Ricky Nelson jumped off the sinking ship and released his first Country Music record.

Ricky Nelson was the second most popular star of the R 'n' R era.

Either of the above dates will do, but about that time Rock 'n' Roll died.

Sha Na Na and others were "revival artists". Punk and Reggae are art forms of their own.