Chicago in Memphis at the Mid-South Coliseum. August of 1971. Tickets were $4, $5 and $6. I had just graduated from high school and this was my first rock-n-roll show.
I suppose I should add that I went to the Grand Ole Opry and lots of country music shows with my folks through the years. Even saw Johnny Cash, Carl Perkins, the Carter Family and the Statler Brothers in 1968. But the Chicago show is what I consider the first.