Led Zeppelin headline the Summer Pop Festival, alongside acts such as Johnny Winter, Jethro Tull and Buddy Guy.

Distant Drummer review excerpt: A notice was tacked on the door of each dressing room at the Spectrum last weekend requesting that performances be kept under thirty minutes each. The explanation given was that the police commissioner, fearing a rock-inspired riot, wanted the show over by 11:45P.M. The truth was that the Spectrum management, having already dropped a bundle in the three part pop festival, didn't want to lose another $1000 in overtime charges to the union employees, etc. The result was that in the few instances where the groups got cooking for the small crowds, the management literally forced them off the stage.

Led Zeppelin had to beg the crowd to let them off. They cited the "commissioner's order" as the cause for the abrupt and mutually disappointing conclusion to their set. [D.D. / 7.17.69]