They show up half way in, but first we see Cab Calloway. A great singer and band leader who almost stole the show in the 1980s Blues Brothers movie. After I saw that film as a young man, I went looking for his earlier work and that got me interested in 30s jazz. The Nicholas Brothers were an amazing dance duo as you can see here. They show up here and there in old Hollywood films. I recommend searching YouTube for their clips.