When you walk out the exits of a major concert at Golden Gate Park onto 30th Avenue, usually you hear a chorus of vendors hawking steaming-hot bacon-wrapped hot dogs. But this weekend after the Dead & Company shows, the calls were something entirely different: “ice cold fatties.”

Fans of the Grateful Dead are pouring into San Francisco for three days of concerts and festivities marking the 60th anniversary of the scruffy jam band that came to embody a city where people wore flowers in their hair and made love,