Aerophone AE-20, AE-20W: How can I turn off keys that I don't use?

The Aerophone AE-20/AE-20W allows you to disable keys that are not in use, to prevent them from being pressed accidentally.

1. Press the [MENU] button.
   The menu screen appears.
   
2. Use the [-] [+] (◀/▶) buttons to select “Key Function” in the System parameters.
   
3. Press the key you want to turn off.
   The name of the key you pressed appears after “Key Function”.
   
4. Press the [MENU] button to move the cursor to the lower row.
   
5. Use the [-] [+] (</>) buttons to select “Off”.
   
6. Press the [SCENE] (▲/▼) buttons to return to the scene screen.