The Chicago Dancing Festival is a celebration of movement that takes place this week. It starts tonight with an Opening Night Gala & Benefit and continues through Saturday. All of the events, with the exception of the Gala and the Last Dance, the (appropriately) last event of the series, are free. There are still tickets to a few of the events, including the lunchtime Moderns at the Harris Theater, and Masters at Auditorium Theatre, but most of them are waitlist only. Movies, a day of dance-themed films, is not ticketed so you can drop in any time between 10am to 6pm to see films like “Invitation To The Dance” with Gene Kelly and “A Dancer’s World” with Martha Graham. The Celebration of Dance in the Jay Pritzker Pavilion is the grand finale of the week and seating in the pavilion begins at 5:30pm.