Poet and artist Carlos Cortez was best known for his stark wood-block and linoleum prints, influenced by Jose Guadalupe Posada, so-called printmaker to the Mexican people, and expressionist German artist KŠthe Kollwitz. A Chicagoan of Mexican and German descent, Cortez was a lifelong member of the Industrial Workers of the World. His text-driven, pedagogical art, which has been shown at MOMA and the Smithsonian, is rough, flat, crowded, and often symmetrical, pointedly indifferent to "good design" in a way that's both antibourgeois and very American. His approach to agitprop can be seen today in the posters of the People's History Project and in Josh MacPhee's massive traveling group poster exhibit, "Paper Politics." Cortez died in January at age 81, and his work is also now part of two shows. "Dia de los Muertos" (closing December 11) at the Mexican Fine Arts Center Museum includes works by Cortez, other artists' homages to him, and a re-creation of his studio. His art is also the main attraction of "Here Are the Voices," organized by the Chicago Couriers' Union and the Pilsen gallery Casa de la Cultura Mestizarte. The show runs through December 16 but tonight they host a good old-fashioned, undeodorized lefty jamboree--a benefit party for bike messengers, the Wobblies' most recent organizing project. Speakers reflect on Cortez's work, and musicians from the Old Town School of Folk Music lead some Wobbly-style sing-alongs. There will be food (courtesy of Logan Square's El Cid restaurant) and other music as well. No specified donation, but a hat will be passed. Mexican Fine Arts Center Museum, 1852 W. 19th, 312-738-1503. Casa de la Cultura Mestizarte, 1440 W. 18th, 773-317-0036. Benefit party Fri 12/9, 6 PM, Acme Art Works, 1741 N. Western, 773-278-7677, donation requested.