Global Union

From their political beginnings as the 80-piece group the All-American Anti-War Marching Band, Mucca Pazza has evolved into the biggest party act in the Midwest, playing sets that unfold as full-fledged halftime shows. The ensemble, now pruned to a still impressive 30-or-so members, dresses in marching-band uniforms, complete with cheerleaders, and has earned gigs on “Late Night with Conan O’Brien” and at Lollapalooza. With their gypsy music undertones, this Chicago group makes an unorthodox but fitting opener for this weekend’s Global Union world music festival in Bay View’s Humboldt Park. Performing today are Mucca Pazza at 1 p.m., Lod de Abajo at 2:30 p.m. and Watcha Clan at 4 p.m.