Your First Concert was.....


My first concert was Arlo Guthrie at the Shaffer (sic) Music Festival in Central Park, NYC. It cost 2 bucks and it was for his "Running Down the Road" album.
dreadhead
Black Sheep in the early 70's with Lou Gramm on vocals well before Foreigner came around.
Wagner Walkure, Seattle Opera 1974. The next year the whole Ring in english and German, then the next year as part of Sigfried, manually operating Fafner the Dragon.

But my first concert of the sort you're talking about was Talking Heads (and some video thing) at the Mudd Club, NYC 1978. My most fun concert was standing right in front of the Gang of Four (spring of 1980) in a tiny U.C Davis cafeteria side-room.

Gregg
The Beatles, Cleveland Municipal Stadium, August 14, 1966. I was 12 and went with my brother's friends. My next concert was five months later....The Monkees, Jan 15, 1967,Cleveland Public Auditorium!! (Not my brother and friends this time; me and two neighbors) Both were scream fests and I could barely see them.....BUT...I was there.