Swedish sisters Johanna and Klara Söderberg have taken what, in the era of TV talent shows and Internet stars (they were once YouTube sensations themselves), has become a rare path to major-label success.

Their hard work and growth within a trusting and nurturing indie label climate have helped develop and mature their sound from the enchanting folk of their debut to the polished Americana that dominates Stay Gold.

Making the jump from Wichita to Columbia Records for their third full-length has given the duo the scope to dream bigger, and that's exactly what they've managed here with an assured and comprehensive collection of songs.

Noticeably more expansive than any of their previous work, Stay Gold has a rich texture of classic country instrumentation and stirring string arrangements, matching their soaring vocal melodies.

They were first noticed when a charming woodland set of acoustic Fleet Foxes covers gained attention for their beautiful vocals, which are still the main draw on this release, with their close harmonies again empowering every song.

The timeless chorus adorning "Cedar Lane" sets the song up for a belting finale, and the closing salvo "How could I break away from you" feels bold yet reassuring.

There is plenty of introspection here that sees the sisters focus on their experiences and journey thus far, and being on the road since they were just teenagers has undoubtedly shaped the defiant slow burner "Shattered & Hollow" and the wandering dreams and vulnerability that seep into "Waitress Song." Despite the obvious shift toward a country-influenced sound with a real romping, foot stomper in "Heaven Knows," there are still folk ballads here -- "Fleeting One" and "A Long Time Ago" -- that show the delicacy and heartbreaking capacity of First Aid Kit.

With a genuine sense of melancholy that is far beyond their young years, the Söderbergs have taken the mild success of their sophomore record, Lion's Roar, in their stride, and with the expert hand of Bright Eyes' Mike Mogis once again producing, the lush harmonies and melodies of this album show that they are worthy of a place in the mainstream.