This is one of the later Vitaphone shorts--known as a "Melody Master". These later musical shorts generally were more straight forward and had simpler sets and no real story to tie it all together--just a famous band of the day doing their stuff.
For the most part, the music played by Glen Gray and the Casa Loma Orchestra was pretty ordinary--though I did like the zippy pace. However, everything came off much better because of the director's amazingly artistic touches. The use of shadows, mirrors, moving sets, camera angles and lighting really made this one looked great. Also, while it wasn't exactly politically correct (listen to the words and you'll know what I mean), "The Darktown Strutters' Ball" was a definite highlight--very peppy and well done.