I COULD HAVE DANCED ALL NIGHT key F 2:33
4 bar intro and vocal in at 7 seconds with a bright Rhumba feel, once through and then 2nd time through the feel changes from 1:09 to swing, continue in this feel and then at the bridge, from 1:44 the feel changes back to a bright Rhumba, staying in tempo and from 2:10 extend the last line - "danced, danced, danced (2 3 4 1 2) all.. night" and finish.
Check out the demo below, with the spoken word "Demo" throughout, because it's an extra long demo.

MP3 DEMO:
F2883. I COULD HAVE DANCED ALL NIGHT - F Piano
key - F - vocal range - F to Bb
The wonderful showtune from the musical "My Fair Lady" in an intimate piano only arrangement, with changing feels from bright Rhumba to gentle swing and back again for the finish.