In an installation-based musing on the requisite collaborations between the “protagonists” of the art world (artists, collectors, gallerists, and critics), local artist Christopher K. Ho riffs on art-world ritual (notice the red-dotted title) and even sculpts gallerist Edward Winkleman in the nude (in a studied, classic Greek sculptural stance, no less.). Happy Birthday l will be up at Chelsea’s Winkleman Gallery through next weekend. —Rachel Wolff