While the insane details of manic-depressive pop savant Daniel Johnston's troubled life make for gripping viewing, the best thing about Jeff Feuerzeig's excellent documentary is his refusal to romanticize Johnston's mental illness. Instead of banal commentary about an artist and the society who just doesn't get him, Feuerzeig presents Johnston for what he is: a talented but deeply tormented singer-songwriter who, in the process of writing childlike songs about Casper the Friendly Ghost, King Kong and a boxer named Joe, finds words for a pain and isolation few are unlucky enough to experience. Feuerzeig begins by tracing this "outsider" musician's seemingly ordinary West Virginia upbringing by conservative Christian parents who worried about their son's preoccupation with art, music and Super-8 films, fearing his idleness would turn Johnston into an "unprofitable servant" of the Lord. After an unprofitable year at Abilene Christian College, during which symptoms of his manic depression first began to appear, Johnston returned home to attend a local branch of Kent State University before running away with a carnival. Winding up in Texas in the mid-'80s, Johnston began hanging around the burgeoning Austin music scene, landing a job wiping down tables at McDonald's and pursuing his seemingly delusional dream of becoming a big star and appearing on MTV (which, bizarrely, he did). Johnston began circulating such aptly titled, home-recorded cassettes as Songs of Pain and More Songs of Pain and soon captured the attention of Austin scenesters and a supportive press. But as Johnston's fame grew, so did his preoccupation with the devil and mental instability, a form of manic depression with paranoid ideation that was greatly exacerbated by heavy drug use. Johnston's behavior grew increasingly erratic and violent, and sudden, destructive outbursts were soon followed by arrests, hospitalizations and disappearances. Johnston's compulsion to tape-record not only his music but his Satan-obsessed musings, combined with the audio-cassette letters he sent his friends, means that Feuerzeig has a remarkable wealth of firsthand material on which to draw. The recordings he includes — like Johnston's mother's hellfire and brimstone harangues — help put Johnston's life into sharper perspective. And then, of course, there's the music, Johnston's deceptively simple songs with naive lyrics sung in a quavering nasal pitch with only piano, organ or clumsily strummed guitar as accompaniment. The casual listener is easily put off, but by the end of the film, even a newcomer can see the magic that made fans of Kurt Cobain and Sonic Youth and led the estimable Yo La Tengo, Pearl Jam and Wilco to cover Johnston's remarkable body of work.