There’s no guarantee a 1978 film about a 1958 musician will hold up decades after its release, but “The Buddy Holly Story” remains an easy watch. Of course, the biopic is assisted by generous helpings of Holly’s music. The film, which traces his career arc from small-town Texas beginnings to tragic death, echoes the timeless simplicity of Holly’s music, possessing an unscripted feel and casual irreverence. Gary Busey’s performance is riveting. Not that it’s perfect. There’s also a bit of a small, TV-movie feel and the narrative is burdened by cliché friction within The Crickets as Holly’s star takes off.