Mack The Knife
Louis Armstrong
We're in true jazz territory now.
There's some chord shapes here that you might not be used to.
If you're having trouble keeping up, remember to isolate and practice each difficult transition separately.
If you're enjoying playing songs in this style, I recommend trying to break down the chords and understand them intervallically.
The more chords you can get into your fingers, the easier it will become to learn other jazz tunes!