"What'll We Do" ("What'll I Do") is a song originally performed by Irving Berlin that is covered by The Chipmunks in the Alvin and the Chipmunks episode The Incredible Shrinking Dave.
Lyrics
The Chipmunks:
What'll we do?
When you are far away
And we are blue
What'll we do?
What'll we do with just a photograph
To tell my troubles to?
When we're alone
With all we dream of you
That won't come true
What'll we do?