Stumbling onto a surprise pleasure is one of the accidental benefits of New Orleans' typically comatose summer calendar. A self-styled "psychotic cowboy" band out of Portland, Oregon, with one self-released album and one single to its name, Roselit Bone isn't a name that jumps off music listings. The cover art for those two records is what piques curiosities. For 2014 LP Blacken & Curl, it's a starkly gorgeous Violet Aveline painting of a blazing cottage filling the dark sky with billowing smoke on the Oregon Trail. May's Dreamless Sleep, a split 7-inch with Jenny Don't & the Spurs, does that one better, with an '80s mall-capture Glamour Shots portrait of the perfectly mismatched foursome in dated Western wear — suggesting second runners-up in a karaoke cover contest of Carter Burwell's early Coen Brothers soundtracks. Strangely and supremely, this is also what lies inside the blackened, curling former: a confluence of the ominously neon dive-bar noir from Blood Simple with the frantic Huggies-stickup yodeling of Raising Arizona. Meanwhile, "Dreamless Sleep" is such an on-point, unironic throwback country waltz, it makes you wonder if those actually are their real clothes. There's only one way to find out. Opening is Guts Club, aka mold-soul Lindsey Baker, whose assuredly unassured Shit Bug (Moderate Fidelity) is the year's best local surprise. Mr. Universe and Phil the Tremolo King round out the tumbleweed bill. Tickets $5.