Now in its fifth year, Debacle Fest offers three nights of adventurous music from local and national acts. Tonight’s opening salvo includes some of the greatest talents ever to play Debacle, including Mark McGuire, Sean McCann, No UFO’s, Brain Fruit, Brother Raven, Panabrite, Megabats, Secret Colors, and Eye Myths. Unconcerned with catchy choruses and conventional song structures, these musicians opt for restless tonal exploration and gnomic evocations of rarefied beauty. With Debacle’s cabal of sonic mavericks, altered states are the new normal. (Black Lodge, www.debaclerecords.com, 8 pm, $10 adv/$12 DOS)