There was a Rock and Roll show at Varsity Stadium in Toronto, either the late '60s or early 70s.?

One of the Acts that I remember were Crosby, Stills and Nash, In what year did this Festival take place?There was a Rock and Roll show at Varsity Stadium in Toronto, either the late '60s or early 70s.?
you are probably thinking of the toronto rock and roll revival that took place in 1969.for more details read this link:http://en.wikipedia.org/wiki/Toronto_Roc鈥?/a>