Changes

This is another tune by the very productive songwriter Walter Donaldson, with some tricky changes of key in the middle. It’s well illustrated on the sheet music cover.
If you want to hear the classic version with a full orchestra, look out for Paul Whiteman’s featuring Messrs. Bix Beiderbecke and Bing Crosby!
It has a verse, a chorus, and a so-called ”patter”.
Here are the lyrics of the chorus:
He plays those beautiful changes in diff'rent keys
Beautiful changes and harmonies
He starts in "C" then changes to "D"
He's fooling around 'most any old key
What's that? Hear that minor strain?
That's it! There it goes again,
There's so many babies that he can squeeze
And he's always changin’ those keys.