To put it as charitably as possible: I have, uh, mixed feelings about the Grateful Dead. It turns out Jerry Garcia did, too, and the final stretches of Long Strange Trip—Amazon’s four-hour documentary covering the 30-year career of the starter-yeast of all jam bands—examine the guitarist’s difficulty with his role in the most successful cult band in history. Garcia’s decline and death make for a moving conclusion to director Amir Bar-Lev’s film, but like the Dead’s live shows, you’ll have to sift through dead ends, hazily presented thoughts, and some flat-out bad music to get to the good parts.