“I Hear A Rhapsody” is a tune written by George Fragos, Jack Baker and Dick Gasparre in 1940.
It’s a commonly called standard and great to know. It’s a 32 bar AABA form.
This tune is most commonly played in the key of Eb major.

I Hear A Rhapsody Play Along
Videos to learn the melody/changes for I Hear A Rhapsody