The San Francisco Museum and Historical Society’s next meeting is about sex, drugs and rock ’n’ roll. The occasion is the 40th anniversary of the “The Gathering of the Tribes for the Human Be-In.” The event on Jan. 14, 1967, attended by about 20,000 people, is considered a pivotal precursor to San Francisco’s famous Summer of Love.

At 7:30 p.m. Tuesday, Dave Getz of Big Brother and the Holding Company will reminisce with others who made their way to the “Be-In” in a lecture-discussion at the Jewish Community Center, 3200 California St., San Francisco. Guests are encouraged to wear tie-dye and other ’60s attire. A reception with photos and film clips precedes the talk at 7 p.m. Tickets are $5. For information, call (415) 775-1111 or visit www.sfhistory.org.