In the late '90s and early '00s, math rock often meant slick and angry angular post-punks. Even the silly stuff had a dark side (see Mr. Bungle's California). Today, bands such as Fifty Bird Step remain dedicated to fretboard somersaults and tricky structures, yet there will be no thrashing or yelling. Carefree Afropop melodies frolic atop the snap of clean guitars and upbeat, danceable drums. This will be Patrick Cortes' second show as Animalweapon, a study in polished down-tempo digitalism. —Corbie Hill