I'd like to recruit djangobooks detectives to investigate a question ? is there any band that modulated up a minor third in the B section of this tune, earlier than Django's recording? They play it in F https://www.youtube.com/watch?v=a6hsUrAoAAQ In the B section they go to Ab (most bands and charts go to Eb). The clarinet plays the melody a fourth higher than usual here.
It's a Cole Porter tune from 1935, Django's recording is 12 years later in 1947. Earliest recorded version I could find https://www.youtube.com/watch?v=CvWyhNX3pLc <-- which is a fabulous arrangement by the way, love the ascending thing going on in the harmony there, and all the little details the string section is adding.
I'm interested to know if there was some other version they were familiar with, or going to Ab was a novelty from this band, and whether it was intentional or just a goof up (perhaps somebody called the tune spontaneously and they were figuring it out on the spot). Maybe a longshot, for any woodwind players: is there some technical reason the bridge melody doesn't work well for clarinet in that key?
(broken out from http://djangobooks.com/forum/discussion/17370/ascending-lick/p2 so as not to sidetrack that discussion)