In between last Jazz Fest and this one, the Deslondes have released their first full-length album (self-titled, on the New West Records label) and spent quite a bit of time on the road. The Americana quintet isn’t new at this; first known as Sam Doores and the Tumbleweeds, they’ve been honing their songs and show together, with some shifting in membership, for close to six years. Bumped up to the Fais Do Do stage this year, the group still showed the kind of growth that comes from close focus.

A major standout was multi-instrumentalist Mat Davidson, an old friend of band cofounder Sam Doores, on fiddle, electric guitar and pedal steel; he ramped up the rock energy of the fairly gentle string band, whose amalgam of country blues and folk is built on taut, twining harmonies and shuffling, old-time dance rhythms. Davidson injected the proceedings with weird, wobbly, almost psychedelic runs on the steel and hot guitar licks. (“He got an electric guitar, and now he’s rocking too hard,” Doores noted with amusement.) But maybe the Deslondes are themselves veering towards rock n’roll: a new song, “This Ain’t A Sad Song,” featured rumbling surf guitar and a boom-boom girl-group beat.

Everyone expects plenty of tributes to Prince from the Fair Grounds stages this year (so far Friday, the Hot 8 Brass Band closed its set with a shout of “Rest in peace, Prince,” Kermit Ruffins took a crack at covering “Purple Rain” and Grace Potter unleashed a long list of Prince covers) but not, perhaps, from the Americana-formatted Fais Do Do stage. The Deslondes’ dedication to the Purple One – a sweet, soft and plaintive take on the old hymn “What Are They Doing In Heaven Today?” – was definitely not the funkiest eulogy of the day, but surely was one of the most heartfelt.