Hey Internet, Whistle Along!
In this performance of "Tonight You Belong to Me," current Mental Floss cover model John Hodgman and
feral mountain man rock star Jonathan Coulton deliver a sweet duet, at one point inviting the listener (ahem, the Internet) to whistle along. Won't you whistle along with them?
See also: coverage of roughly the same thing from 2008, Sweetest Song Ever: "Tonight You Belong to Me."