Artist Jim Melchert describes the creation of Changing Walls in 1971 with the participation of fellow Bay Area conceptual artist Howard Fried. The piece features a sequence of 80 slides projected at life size on the wall. Melchert's slide projections and performances in the 1970s often involved his community of artist friends and family members. One year after its international debut at the exhibition Documenta 5 (1972) in Kassel, Germany, Changing Walls became the first time-based media artwork SFMOMA acquired for the collection.