Open Call for all fun seekers! The annual Mp3 Experiment is a participatory audio adventure produced by ImprovEverywhere where attendees use a smartphone app to listen to synchronized secret instructions in a public space via headphones. It's just about the most fun thing you can do with a crowd of thousands of strangers. The event, as always, is free and open to all, so help spread the word! RSVP on Partiful to participate and to receive important updates leading up to the event