Your first concert was to see who and when?

1970 or 1971, Linda Ronstadt and Michael Nesmith @ Blackham Coliseum in Lafayette Louisiana. Enjoy the music

Jefferson Airplane at the Electric Factory, Philadelphia, November 1968.

My first live show was Bad Company at the Long Island Coliseum in 1977. The Climax Blues Band was the opening act. My friend's mom dropped us off and picked us up. At 13 we thought we were pretty damn cool!
 

some amazing shows on this thread! 

Foreigner, 12/3/78, Boston Gahden

1812 Overture & a Tchaikovsky Symphony at the Royal Albert Hall. I do not remember which orchestra was playing.  It was 1958 or '59. The cannon's echo may still be running round in the Gods!

I was in the local C of E youth club for about 5 years and a few times a year we would go to London, usually the Albert Hall or RFH.  In addition to "classical" concerts (baroque through romantic & 20th century periods) I remember Acker Bilk's Paramount Jazz Band and Monty Sunshine's "Trad Jazz".  We also went to the MJQ at the RFH in (I think) 1961.