'Frozen' Short 'Get a Horse': Walt Disney's Voice The new Disney princess movie, Frozen, features lots of big-name voices, like Kristen Bell, Idina Menzell and Josh Gad. But the short cartoon that shows before Frozen starts contains the most famous voice of them all: Walt Disney as Mickey Mouse. Lauren MacMullan, director of the Get a Horse! short, says she has always been a fan of the inventiveness and flexibility of the "rubber hose" style of animation, the early look exemplified by Steamboat Willie's Mickey Mouse and his hose-like arms and legs. "To me it's an era that seems really fresh and full of possibility." She decided that a found-footage concept would be the best way to revisit Mickey, Minnie and the look that made Disney famous; the challenge was to make the film seem modern at the same time. For that, she turned to a through-the-screen plot, partially inspired by Woody Allen's classic The Purple Rose of Cairo. Mickey and friends would move between the old-timey world and a newfangled one, showcasing Disney's classic style as well as the animation that Frozen audiences would expect. MORE: 10 Things You Probably Didn't Know About Walt Disney It's not unusual for animators to use sample voices during the storyboarding process, planning to replace them later, and MacMullan decided that - given her access to the original Disney shorts by which she had been inspired - she'd just use that old Mickey voice, which had been performed by Walt himself in many early shorts, as the sample. It was at the next step in the usual process, thinking about hiring an actor to voice the lines for real, that things got unusual. Disney had not been a trained actor, and MacMullan felt that lack of training could be heard, in a positive way, in his voice; it was too easy for other Mickey Mouse voices to sound like a parody of the original, and any sarcasm would take the short in the wrong direction. "At some point we said, "What if we went out of our way [to use that voice throughout]?"" recalls MacMullen, whose previous credits include storyboard work on Wreck-It Ralph and The Simpsons,. His voice has that quality of innocence, of doing everything for the first time. MORE: Richard Corliss reviews Frozen But, while working for Disney meant access to old tapes and a stable of animators trained in the old style, using the founding father's voice was easier said than done. After all, he hadn't had the Get a Horse! script in mind when recording his own Mickey bits. The project required an assistant editor to comb through what MacMullan says was every single line that Disney ever uttered as Mickey, looking for words that matched their needs. Not every line was available. In some cases, that meant changing the script: MacMullan had wanted Mickey to say "Come on, everybody!" but the best they could do was a whistle that summoned his friends. In other cases, the team was able to cobble together words from various sounds available. When Mickey goes modern and sees that his pants, once black-and-white, are red, his exclamation is really a mash-up of the sounds rrr and ed. "That one word took maybe a week and a half," says MacMullan. While archive sounds are also used for Minnie Mouse and Peg-Leg Pete, new actors stepped in to fill in the gaps for those characters. Animation is, in general, a time-consuming process, and not just because of Disney's voice. After all, MacMullan first pitched Get a Horse! three years ago. But the time invested is worth it, she says, and proves that even the most up-to-date audiences can enjoy one of the oldest acts in animation. "One of the best things about sitting with an audience to see this," says MacMullan, "is that they're laughing." MORE: Do Animated Female Characters Need to Be "Pretty"?