It's not easy being a great folksinger — you've got to walk a tightrope across a musical minefield where the slightest misstep can find you wallowing in post-Joan Baez warble, drowning in affectation à la Martha Wainwright, or perishing in any number of other aesthetic pitfalls. Only a precious few learn to master that high-wire act; Kate Wolf, Linda Thompson, and Iris DeMent are some of the names on the short list, but Golden Apples of the Sun makes a strong case for the addition of Caroline Herring. Pitched at a point equidistant between honeyed and throaty, her warm, measured tones consistently deliver just the right emotional effect whether she's transforming the songs of others or bringing her own to the table. The ominous minor-key strum that introduces her version of the Cyndi Lauper hit "True Colors" is a sonic red herring that makes you certain you're about to hear Nirvana's "Come as You Are," but Herring's takeover of the song is so ...