Documenting Dolly Parton with 20 tracks isn’t easy — she’s gone through enough artistic shifts and identity adjustments to fuel several recording careers. This anthology does a superior job at laying out the basics, drawing mostly from Parton’s eventful years with RCA. Her self-penned tunes from the ‘70s are a high point — “Joshua,” “Coat of Many Colors,” and “The Bargain Store” are classics of the country idiom, filled with detail and infused with heart. With “Jolene” and especially “I Will Always Love You,” she reaches out to the pop market without losing the East Tennessee sweetness so essential to her music. Parton’s later releases are more problematic — the songs from this era included here (especially “9 to 5” and “Here You Come Again”) are the best of a decidedly mixed batch. Her ‘80s work veers from glossy confections (the Kenny Rogers duet “Islands in the Stream”) to finely-wrought art pieces (“To Know Him is to Love Him,” sung with Linda Ronstadt and Emmylou Harris). Parton’s assertive-yet-tender vocals and expansive personality remain a constant, even when her sound changes from Appalachian homespun to L.A. sleek.