By Eric Renner Brown
March 10, 2017 at 12:00 PM EST

Long Strange Trip, the sprawling documentary about psychedelic pioneers the Grateful Dead, arrives on Amazon Prime Video on May 26 — but before that, it’s making a tour stop at SXSW on Friday night. The documentary, directed by Amir Bar-Lev (The Tillman Story) and executive produced by Martin Scorsese, charts the group’s rise and multi-decade career. In the exclusive clip above, bassist Phil Lesh and late guitarist Jerry Garcia discuss how the band settled on its name, after an initial stint as the Warlocks.

“Jerry was wandering around, kind of randomly,” Lesh says, “he picked this dictionary, Funk & Wagnalls, I think it is.” When Garcia cracked the volume open, the first thing he saw were the words “grateful dead” — a moment of randomness that would define a half-century of subsequent music.

Long Strange Trip made its world premiere earlier this year at the Sundance Film Festival. Interviews in the documentary include the band’s members, lyricists John Perry Barlow and Robert Hunter, Minnesota senator Al Franken, and numerous writers, crew members, and industry executives who worked with the Dead throughout their career.

Garcia died in 1995, but the group has continued in numerous iterations, playing a string of “Fare Thee Well” shows as the Grateful Dead in 2015. Since then, members of the Dead have toured with John Mayer as Dead & Company.