In case our resident film blogger Sarah Ando’s Valentine’s Day post on big-screen love stories left you pining for a larger “West Side Story” experience than what our DVD allows, Chicago’s Music Box Theater has you covered. The historic Southport theater kicks off its 70mm Film Festival tonight with a showing of Hitchcock’s “Vertigo.” “West Side Story” will be shown in all its cinematic glory three times over the course of the festival, which runs through February 28th. What is so special about 70mm? According to the Music Box, “it is a format that allows for more information and more visual clarity than its 35mm counterpart. There is a depth to the image that is unlike 35mm, and certainly very different from digital projection.” Get your tickets now.