Sour Bridges describe their sound as “browngrass”: bluegrass but with a dirtier, more raucous edge to it. The Austin band debuted in 2010 with Workin’ On Leavin,’ a charmingly lo-fi take on classic country. 2013’s Catfish Charlie mixed their exuberance with a hard-earned honky-tonk spirit, coming after years of gigging around Texas. Later this year, Sour Bridges are set to release a self-titled album, and all this month they’ve held down a residency at the Cactus Cafe in preparation. Their final Cactus date is tonight, and in the meantime, a song of the day from their recent Studio 1A session will get you ready. “Fine Life” is rough around the edges, but there’s just enough sugar in the band’s multi-part harmonies to keep you coming back for more.