Most of the time it’s hard to synchronize a personal schedule, let alone with someone else. But Earthdance, founded in 1997, brings over 250,000 people around the globe together; the defining moment each year is a synchronized link-up as each Earthdance venue around the world plays the same song, “The Prayer for Peace,” at precisely the same time. Highlights of the local event include Ziggy Marley, Ghostland Observatory, the Coup and Balkan Beat Box; the festival runs Friday–Sunday, Sept. 23–25, at the Solano County Fairgrounds. 900 Fairgrounds Drive, Vallejo. $45–$70 daily; weekend passes available. 415.256.8499.