In 1965, the Grateful Dead attended their first acid test

The Warlocks, the San Francisco band that would soon become the Grateful Dead, attended their first Acid Test on 27 November 1965 at organiser Ken Babbs’s home in Soquel, California. The informal gathering brought the musicians together with members of the Merry Pranksters and helped connect the band to the psychedelic scene that would grow around the Acid Tests.

Accounts differ on how much the band played: Phil Lesh recalled trying an electric guitar briefly, while Jerry Garcia said there was no proper performance and everyone was both performer and audience. The event was a modest house party rather than a planned concert; days later, Garcia chose the name Grateful Dead after learning another band was called the Warlocks. By 1966, the group was taking part in larger, more organised Acid Tests.