Most Helpful Girl
Wow, there are so many!! Rolling Stones, Creedence Clearwater Revival, Jimi Hendrix, Nina Simone, Bob Dylan (I think he'should from that decade too), Janis Joplin...
But I have to pick two best, I can't help it, there both great in their own way: Frank Sinatra and Bruce Springsteen (this last one was just beginning then, but he's always been fantastic).
Very long answer for a direct question but I had to mention all of them :-)
Most Helpful Guy
Rolling Stones are #1 for sure, CCR, The Doors, and The Who are great too. Black Sabbath, Led Zeppelin and Deep Purple were more 70s but they did start in the late 60s.
This is definitely #1 for me-