Bill Murray is no stranger to making us laugh, and his iconic lounge singer alter ego, Nick Winters, never fails to entertain. In a memorable appearance on the Late Show with David Letterman, Murray took things up a notch by performing Olivia Newton-John’s hit song “Physical.” At the time, Newton-John’s recording was still fresh, having been released just a few months earlier, and would later go on to be named Billboard’s most successful single of the 1980s.