1. Lengthening or shortening the tube: A longer tube produces a lower pitch, while a shorter tube produces a higher pitch.
2. Changing the diameter of the tube: A wider tube produces a lower pitch, while a narrower tube produces a higher pitch.
3. Adding or removing holes in the tube: Adding a hole raises the pitch, while removing a hole lowers the pitch.
4. Changing the material of the tube: Different materials have different resonant frequencies, resulting in different pitches. For example, a metal kazoo will produce a higher pitch than a plastic kazoo.
5. Using different membranes: The type of membrane used can also affect the pitch of the kazoo. A heavier membrane will produce a lower pitch, while a lighter membrane will produce a higher pitch.