Rolling Stones at Madison Square Garden, in 1972 or '73 (Stevie Wonder was the opening act).

One of Elton John's very first live U.S. appearances at the Fillmore East in NYC. The headliner for that show was Leon Russell, which is who I had come to see.

And just about every "classic rock" band you can name from 1969-1971 at the Fillmore.