Kazoo

The kazoo is propaply one of the simplest - and most anoying - instruments. Therefore I love them. This approach consists of two easy to print parts (I used an 1mm Nozzle with .4mm layer height).

Also you will need a Membrane which will be insertet in the indentation on the bodypart and will be held in place by the ring. Membranes should be made from thin paper. In my tests receipt (thermal) paper and thin catalogue paper worked best. 

If the kazoo don't buzzez well you can try sanding down the indentation a bit further. If you sanded it down too far may try thicker paper like regular printer paper. 

Happy music-making or people-annoying

Edit:

Paul La Rosa remixed my design adding a small knob for easier alignment of the sleeve so you also may want to check out his remix: 

https://www.printables.com/de/model/599687-lu-pos-kazoo-remixed/comments