John Cage’s Chicago fans are marking his 80th birthday with a week of revelry and tribute. For those who have come to admire Cage’s wide-ranging artistic and musical endeavors, every event next week–most of them are taking place on the Northwestern University campus, a hotbed of Cage scholarship–is a chance to indulge in hero worship. For those curious about the highly touted Cagean aesthetic–a remarkably iconoclastic outlook that has had profound influences on American avant-garde culture–I recommend the following performances: Cage reads from two new works, The First Meeting of the Satie Society and Overpopulation and Art, Sunday at 3 PM in the Rubloff Auditorium of the Art Institute, Columbus and Monroe; 443-3711. A recital of Cage’s piano music featuring two works from the 40s and two from the 80s, with pianists Anthony de Mare and Nana Matoba and flutist Karen Bogardus takes place Monday at 6 PM at the Arts Cluv of Chicago, 109 E. Ontario; 787-3997. Last but not least, there’s a multimedia performance of Europera 5, the latest in Cage’s series of theatrical works which use basic elements of opera as guidelines for the performers, who are really the ones to determine what happens onstage. Pinaist Yvar Mikhashoff, soprano Sunny Joy Langton, and baritone Bruce Hall will perform, and Amnon Wolman, head of Northwestern’s computer-music lab, will direct. Tuesday, 7:30 PM; Pick-Staiger Concert Hall, Northwestern University, 1977 Sheridan Rd, Evanston; 708-491-5441.