See Darius Rucker and Tourmates Go Old-School With Doc Watson Cover

Brothers Osborne and A Thousand Horses join their tour boss for a backstage collaboration on "She's Gone Away."

As Darius Rucker's Southern Style Tour rolled across the country this summer, some of the trek's most unexpected collaborations took place behind the scenes. The eclectic stage lineup, which also included CMA-nominated duo Brothers Osborne (John and T.J.), A Thousand Horses and Brett Eldredge, represents a wide array of musical influences and their frequent behind-the-scenes jam sessions, many of which took place in the Osbornes' dressing room, became online sensations.

In spite of the limited downtime the acts had available as the tour progressed, their faithful rendering of the Western swing classic, "San Antonio Rose," captured backstage at the June 20th stop in Houston, demonstrates the musical camaraderie that all the acts share.

"This tour feels like a collection of friends we've gathered throughout the years," John Osborne notes. "T.J. and I have known A Thousand Horses ever since the very beginning of that band. Six or seven years, I think. They've been at it for a long time, just sticking it out and waiting their turn, and they deserve every bit of their success. I played guitar on Brett's 'Beat of the Music,' too, and love all the guys in his band. It's super fun to get to hang with all my buddies, and when you have all these musicians in the same environment, why not take advantage of that?"

Before the Osbornes wrapped up their portion of the Southern Style trek, they made sure to include the headliner in one of their jam sessions. Rucker is joined by 11 pickers and singers in the above video, which was shot in the Brothers Osborne's tapestry-covered backstage lounge. Although "She's Gone Away," recorded by the late Doc Watson on his 1987 LP, Portrait, is a mournful break-up tune, the snappy arrangement is pure Texas swing, punctuated by twin fiddles, accordion and Dobro, and featuring Rucker's expressive lead vocal throughout.

The Southern Style Tour continues throughout the fall, with A Thousand Horses and David Nail along for the ride. Meanwhile, the Brothers Osborne have a full schedule of tour dates stretching into early next year.