Epic performance

MEDICINE WHEEL Part art installation, part vigil, part ritual and performance, Michael Dowling’s 24-hour World AIDS Day epic marks its 20th anniversary. Kairos Dance Theater opens the event at midnight with a site-specific performance of the provocative “Hydra,” a work about the power of the group dynamic. Pictured: DeAnna Pellecchia and Ingrid Schatz. Nov. 30, 11:45 p.m. (pre-performance procession). Free. Cyclorama, Boston Center for the Arts. 617-268-6700, www.mwponline.org Karen Campbell