The nearly undisputed heavyweight champions of contemporary Americana, David Rawlings and Gillian Welch, return with another haunting collection of deep folk, simultaneously timeless and incapable of being made by anybody else. Under their male-fronted Dave Rawlings Machine guise, the project merely shifts the balance of the pair’s singular twodecade- running partnership, focusing on Rawlings’ songs and singing, but fully retaining the magical feel of the five full-lengths they’ve made under Welch’s name. With Rawlings on the marquee, there is actually less of his conversational Jerry Garcia-like solo-over-or-under-everything approach than usual, if only because he sometimes has to stop and sing. Recorded in a drumless string-band lineup with members of Old Crow Medicine Show and the Punch Brothers, fellow travelers in the never-ending twang revival, Rawlings’ songwriting sometimes bends toward the anthemic, such as the disc-closing “Pilgrim (You Can’t Go Home).” More often, though, the guitarist finds himself in gently surreal, half-mystical modes, occasionally abetted by light strings (“The Weekend,” the 11-minute “The Trip”) or playful sing-song (“Candy”). Always, the music returns to Rawlings and Welch’s particular vocal blend. Rawlings is a fine vocalist and an excellent songwriter, but Welch’s voice is one of the most ghostly of this or any epoch, and to have it float sparingly through each song is to hear it as Rawlings ordinarily uses his guitar—as a counterpoint that allows access to a realm all its own. The skyline of Nashville Obsolete beckons.