Presented by Robert Zagone The mushrooming music scene of late-sixties San Francisco, boasting such mind-expanding groups as the Jefferson Airplane, the Grateful Dead and Quicksilver Messenger Service, didn't just happen live at love-ins and the digs of the Family Dog. There were a fortunate few who knew a good thing when they saw it and shot it on film. Robert Zagone, then an innovative producer of music programs at KQED, had an ear for the righteous band and an eye for its rendering, from the solemn to the outright psychedelic. For tonight's program, he has wiped the Day-Glo dust off his archive to bring us a sonic flash from the past. You'll see: Big Brother and the Holding Company's first TV appearance with a blushingly innocent Janis Joplin; the Jefferson Airplane singing "Volunteer" intercut with antiwar demonstrations; an outdoor concert of the Steve Miller Band with Boz Scaggs; the all-women band, Ace of Cups; an experimental video of the Sons of Champlin that'll make you hallucinate; and, you guessed it, much, much more.