The Grateful Dead, rock band and countercultural standard bearer, appeared at the DuPont Gymnasium on May 7, 1970, a day after playing a short impromptu set in the rain on the steps of the Student Center. With the deep unpopularity of the Vietnam War, more than a few MIT students were protesting the Institute’s close ties with the military. The band’s visit came four months after students occupied MIT President Howard Johnson’s office—breaking in with a homemade battering ram—and three days after the Ohio National Guard shot to death four Kent State students. In a show whose memory is still cherished by many alumni, the band played no fewer than 43 songs for a ticket price of $3.00 (or $3.50 at the show). In the popular Dead tradition of sharing bootlegged recordings, you can listen to those concerts here.