File this one under "Miscellaneous": the Second Annual NYC Main Squeeze Accordion Festival kicks off tomorrow at 2p in Riverside Park on the Hudson at West 70th St. Featured sounds include everything from Balkan, to Rock, to Tango, to Cajun. Admission is free. According to Let’sPolka.com: "Last year, people danced so hard we had to bring ’em home on stretchers!"