I was there in San Francisco in those years. Every weekend brought a triple bill at the Fillmore Auditorium and/or the Avalon Ballroom, with the likes of the Grateful Dead, Jefferson Airplane, Big Brother and the Holding Company, Creedence Clearwater Revival, Quicksilver Messenger Service, Joy of Cooking.

One day in 1968, the first warm Sunday of spring, they closed off four blocks of Haight Street for a block party. The Grateful Dead showed up, backed up a pair of flatbed trucks catty-corner across the intersection of Haight and Ashbury, and gave an impromptu free concert, opening with “Dancing in the Street.”

Wasn’t that a time?