Probably the first rock concert I went to - (I had been to some classical concerts as a child) - was either the Amboy Dukes or Chuck Berry and Bo Diddley - cant remember the timeline in the 60s that well
many concerts towards the end of the 60s that were free outdoor concerts at my college(American Univ) included Grateful Dead, Procul Harem, Richie Havens, Hendrix, James Taylor, Pete Seeger (he's the only one I remember from the Moratorium concert in DC), Allman Bros and many others
In Hawaii I had the opportunity to be working for the only music store in Honolulu and we provided equipment for the Crater Concerts in Diamondhead - I remember being backstage with Fleetwood Mac, Flo and Eddie, Robin Trower, Tower of Power and many more