Often at swing dances you hear "Let's Call The Whole Thing Off" performed by Louis Armstrong and Ella Fitzgerald, but I think it's good to sometimes trace the song back to its orgin.
"Let's Call The Whole Thing Off" was written for the movie Shall We Dance from 1937 with lyrics by Ira Gershwin and music by George Gershwin. In the video clip above you see Ginger Rogers and Fred Astaire dance to the song on roller skates.
When you see the film, the song's introduction makes much more sense than it does when played "stand alone", that's why I most times cut the intro and start playing at "You say either, I say either".
By the way, don't confuse this movie with Shall We Dance from 2004 starring Jennifer Lopez, Richard Gere and Susan Sarandon or the original Japanese version of Shall We Dance (1997) which people say is the better one (I haven't seen the latter).
What do think of Ginger Rogers and Fred Astaire dancing to "Let's Call The Whole Thing Off"? Tell me.