The Americana and folk scenes are full of married or partnered couples these days. Mandolin Orange, the North Carolina duo of Andrew Marlin and Emily Frantz, follows in the footsteps of the couple that started this trend and so many others, Gillian Welch and David Rawlings, although in this case it’s the guy who’s the main songwriter and the usual vocalist. They look outward rather than inward as other couples have, cultivating a classic style with deep evocations of the musical past. Yet, as with Welch and Rawlings, their concerns are completely contemporary.

Mandolin Orange came on the scene in 2009, impossibly young and beautiful, with Frantz often attired in the devastating combination of tank top, shorts, and cowboy boots. Marlin’s lyrics were similarly minimal yet full of unexpected turns of phrase, and it sometimes seemed as though he was taking fragments of classic old-time country imagery of love, loss, and drink and moving them around like puzzle pieces until they fit in some unusual pattern. On their 2010 album Quiet Little Room, they accompanied themselves as simply as could be, with Marlin on mandolin and Frantz on guitar, or Frantz on violin and Marlin on guitar. The overall effect was lean and mysterious in its simplicity.

Mandolin Orange has gotten a lot of attention, and they’ve appeared around the circuit that has unexpectedly made bluegrass, a category into which they fit in general outline, a household word among many young people. They’ve released two more albums on which Frantz has started to sing more and Marlin, after nearly dying in an accidental fall off a dam spillway, has stretched his songwriting a bit: the successfully mysterious “Turtle Dove and the Crow,” from their new This Side of Jordan, neatly weaves the old blues plaint “If fate’s an old woodpecker, I’m a chunk of wood” into a tapestry of newly created old-time images. The duo’s music has also taken on a partly hidden strand of unorthodox Christian belief, much like that of another musical couple, Over the Rhine’s Linford Detweiler and Karin Bergquist.

The Mandolin Orange show at the Ark on September 4 is the club’s annual student welcome show, which is free with any student ID. In the heady week when students return to campus and seek out new experiences in packs, these shows have drawn good crowds and testified to renewed curiosity about musical roots.