Concerts used to be a lot more low-key . . . then Bruce Springsteen came along with his massive, 3-to-4-hour shows, and ruined it for everybody.  At least that’s now Paul McCartney sees it.  Quote, “I blame Bruce Springsteen . . . I’ve told him so!  I said, ‘It’s your fault, man!’ . . . We used to do a half-hour.  That was the Beatles’ thing:  half an hour and we got paid for it!”   Paul says shorter shows were more common in the ’60s, because there were usually several acts on a bill, rather than just a headliner and an opener