Today, 13 participatory musical parades commence all over NYC, and you're encouraged to join the fun with your own tunes and melodic creations. You'll be prompted on what instruments you'll use (or bring) depending on the parade you choose. For instance, if you march with the Flat Foot Flatbush: Nick Horner Family (Grand Army Plaza, Prospect Heights, Brooklyn; 2:30pm), you're encouraged to bring tap shoes if you have them. The Lightmotif: Hiroya Miura (43rd Ave at 24th St, Long Island City, Queens; 3pm) invites all bagpipers, and Prelude: James Holt (William Jay Gaynor Memorial in Cadman Plaza, Downtown Brooklyn; 4pm) asks that you download an app especially for their walk. Pick your parade or hop around—no registration necessary.