After switching to big-name British producer John Paul Jones (of Led Zeppelin fame; he also contributes some instrumental support), this female stringband quartet continues to go wider and deeper in its exploration of acoustic Americana.  On their sophomore release, Uncle Earl's balance contributes to their range. Each of the four is a virtuosic musician, all contributing vocals that blend into the buoyant harmonies of "One True," the a cappella shape-note spiritual "Buonaparte," and the field hymn "Easy in the Early ('Til Sundown)."  While uptempo fare spotlights the sprightly fiddle of Rayna Gellert, banjoist Abigail Washburn sings a stark meditation on mortality in the revival of Ola Belle Red's "My Epitaph," with guitarist Kristin Andreassen illuminating the vocal purity of A.C. Carter's "The Birds Were Singing of You."  As for percussion, Gillian Welch provides guest drums on "The Last Goodbye," and Andreassen's clogging serves as a rhythm track behind Gellert's fiddle on "Sisters of the Road."--Don McLeese