chipmunks would be; the animals were then removed when it was time to shoot, and he used his memory of where the animals were. Visual-effects The Chipmunks were animated by Rhythm and Hues Studios, a company that previously animated creatures for projects such as Mouse Hunt (1997); Scooby-Doo (2002); The Cat in the Hat (2003); The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005); and Babe (1995), the latter of which garnered Rhythm & Hues an Academy Award. As with all of its past projects, Rhythm & Hues used its own software for animating Alvin and the Chipmunks, such as Voodoo and Icy, which was used for placing the CGI into live-action shots; although Autodesk programs like Flame and Maya were used. According to Bagdasarian Jr., getting the look of the chipmunks suited for a live-action setting while maintaining the essence of the cartoon designs was challenging, and it took until September 10, 2006, for the artists to get it right. Hill instructed the artists to make the chipmunks look realistic, but not entirely like chipmunks. In addition to observing real chipmunks offered by Universal Studios, Rhythm and Hues studied all versions of the chipmunk characters from past Alvin media for conceiving, fur-texturing, and animating designs for the film. Human dancers were referenced for animating the dance movements of the chipmunks, and YouTube videos of famous guitarists playing the guitar influenced how Alvin's guitar-playing was animated. High-dynamic-range images of sets were also used for lighting the chipmunks to fit the live-action shots. The most difficult part of integrating the CGI critters in the live-action shots was match moving for instances when they climb on Seville's head. For scenes where the chipmunks interacted with props, some of them were live-action props while others, such as a paper airplane, were produced and animated with computers. Music Soundtrack The soundtrack was released November 20, 2007, three weeks before the film's opening, and contains new versions of old songs such as "Witch Doctor" and "The Chipmunk Song (Christmas, Don't Be Late)" (as made famous by David Seville and the Chipmunks), cover versions of songs such as "Bad Day" (as made famous by Daniel Powter) and "Funkytown" (as made famous by Lipps Inc.) and new songs such as "Coast 2 Coast", "Get You Goin'" and "Get Munk'd". The second track on the album is "The Chipmunk Song (Christmas Don't Be Late)", a