Where so many country blues revivalists sound like tourists or carpetbaggers, Grant Dermody devises his own musical map. An understated harmonica virtuoso and a vocalist of subtlety and warmth, he not only renews an acoustic legacy, but extends it.

Building bridges from a base of tradition, Dermody finds a common denominator for interplay that might appeal to fans of Blues Traveler and other jam bands (the album-opening original “Breakthrough” and the sprightly calypso “The Leeward Slide”) amid homages to influences from Skip James (“Look At The People Standing In Judgment”) to John Jackson (“Boats Up River”).

While a harmonica duet with Phil Wiggins on “Anacostia Two-Step” strips this music to its organic core, the jazzier strains of “It’s Alright” and “What Comes Around” (with its unlikely trio of harmonica, trombone and piano) evoke the improvisatory spirit of Toots Theilemans. For all of the formidable chops displayed by Dermody and his supporting musicians– with Orville Johnson the album’s MVP on a variety of stringed instruments — there isn’t a showoffy note on the fifteen-song set.

Instead, the album celebrates an organic, communal creativity, transcending boundaries of era and category. In “Why You Been Gone So Long”, Dermody transforms a mournful Mickey Newbury staple into a performance that has the spiritual grace of a Mississippi John Hurt tune. With many rivers to cross, Dermody makes an expansive musical landscape sound like an artistic birthright.