There’s warmth and keen observation in the early Appalachian scenes, but this 1980 biography of country singer Loretta Lynn wears thin as it plays on, devolving into familiar showbiz sentimentality. As Lynn, Sissy Spacek captures the fragile, little girl aspects of the singer’s persona, but misses her balancing strength and professional determination—the link between Butcher Hollow and Las Vegas. Tommy Lee Jones, as her husband, continues to excel as a physical performer who makes highly intelligent choices; ex-Band member Levon Helm has a short, stern, affecting cameo as Lynn’s father. Michael Apted directed; with Beverly D’Angelo as Patsy Cline. PG, 125 min.