The first concert I ever attended? New Kids On The Block. No joke. :H I was just a little kid, though, and my family went because my sister was a big fan. Heh, I'm sure my parents hated it.
I could say it was some classical music concert, where i went because of anything else but music, when i was like 10-12, I guess first concerts I went to were at Jazz Cerkno festival in 2002 or 2003...I'm not really sure.