Mournful, elegant, melancholy, and mysterious, the Northumbrian family act is most certainly not a party band; rather their singular blend of traditional folk and jazz-tinged, Celtic-infused pop is tailor-made for those for whom soft rolls of thunder and deep grey skies are a balm to the cruel tempo of the extroverted life. Fresh off of a trio of excellent, largely conceptual live recordings that found the Unthanks taking on the songs of Antony & the Johnsons and Robert Wyatt, collaborating with the Brighouse and Rastrick Brass Band, and exploring the region's rich tradition of seafaring, the group returns with their first studio effort since 2011's Last. Like its predecessor, Mount the Air is a dark storeroom of soft, piano-led balladry peppered with tasteful flourishes of upright bass, soft brush work, and spectral horns and strings, but it's also a far more ambitious outing, sporting two epic ten-minute pieces that flirt with experimental ambient pop grandeur. The first, an original piece built around the opening verse of the traditional folk ballad "I'll Mount the Air on Swallows Wings," is a rich ballad that builds to a sweeping and surprisingly propulsive string-laden crescendo that's anchored by Becky and Rachel Unthank's expressive voices, while the second, the lush "Foundling," dials up the group's more theatrical leanings. Elsewhere the intriguing and (almost) radio-ready "Flutter" flirts with Portishead-inspired trip-hop, and the band plays it straight on a lovely rendering of the traditional folk standard "The Poor Stranger," but as per usual, it's the Unthanks' acumen for crafting highly refined overcast ballads that ultimately wins out, and some of us are all the better for it.