Derek Pressnall is a native of Dunwoody. Since landing in Omaha, Neb., several years back he's been singing and playing guitar with glee-pop troupe and Bright Eyes cohorts Tilly & the Wall. FLOWERS FOREVER finds Pressnall making a dark departure from sunshine pop for an exercise in überart rock 'n' roll. This turn toward propulsive rhythms and textures is indulgent and cathartic and worth checking out Sat., MAY 31, based on the weirdness factor alone. $10. 9:30 p.m. Drunken Unicorn, 736 Ponce de Leon Place. www.thedrunkenunicorn.net.