A half-century ago, 1969 capped a radical, idealistic decade that saw the rise of the hippie generation and the assassinations of John F. Kennedy, Robert F. Kennedy and the Rev. Dr. Martin Luther King Jr. Woodstock, perhaps the most famous concert ever, happened that summer, with free love and drugs serving as backdrops to sets by Jimi Hendrix, Santana, Richie Havens and others.

But another large, raucous rock festival that year became notorious for very different reasons: Altamont. That December, the Rolling Stones and the Grateful Dead organized an impromptu concert at Altamont Speedway, in the golden hills of Northern California’s East Bay, that drew an estimated 300,000 people. Four people died, including a man who was killed by members of the Hells Angels who had been hired to provide “security” for the event.

So much for peace and love.