When Americana duo Shovels and Rope opened their set on Jazz Fest's Fais-Do-Do Stage with the ominous "Swimmin' Time," they sounded a tone that hovered like the rain clouds over the set. It never swamped the show though because the marriage between Carrie Ann and Michael Hearst is at the heart of good time and bad time songs, and its warmth is underlies even their most shadowy moments.

Onstage, they stand feet from each other and sing as much to each other as the crowd. When they swap positions and one moves behind the drum kit, they stop to talk for a moment, apparently pointing things out to each other.

That intimacy made the stage seem more like their back porch. No matter the noise or minor keys, each song came down to the interplay between their voices, which was simultaneously personal and theatrical. They never forget they're onstage, but they don't stop being a couple either.

They also don't stop being who they are. Carrie Ann Hearst's voice is as country as they get, and she comes by it honestly. She dedicated the a capella-with-drums "Fish Assassin"--about backwoods fishing--to her dad.

Still, the set was as fundamentally rock as folk. Their thump would never have occurred to the Carter Family, nor would Michsel Hearst's Velvet Underground-like rhythm guitar for"Bridge on Fire."

The set could have used some of the rowdiness that characterized previous appearances in New Orleans, but it was never entirely absent either. The show suggested that their music is gaining complexity without losing anything important.