Watch the "never-before-seen" Back To The Future audition tapes, featuring Al Pacino, Eddie Murphy, Prince, Robin Williams, Pee Wee and more. But beware: world's scariest, most spot-on Alan Alda impression ahead...

Thank you Saturday Night Live for putting that alternate Al Pacino casting in our minds. And goodness is there nothing Bill Hader can't do? Best impressionist working right now? We definitely think so.

Many thanks to John Siegel for helping us with the video.