Stopping by "The Late Show" on Monday to promote his Hank Williams biopic "I Saw the Light," Tom Hiddleston was confronted with an obvious request, to perform a song.

Despite boisterous applause from the studio audience, Hiddleston turned down host Stephen Colbert, saying, "I do feel like, if you want to see me sing, you should go and see the film." However, a chuckling Colbert viewed that not so much as a rejection, but as a challenge: "We'll see, we'll see ..."

Cueing the band, Colbert launched into the opening lines of the Williams classic "I Saw the Light," and quickly overcame Hiddleston's resistance, leading to a joyful duet turned audience sing-a-long.