1. Open the Mario Paint program and select the Composer icon.
2. You will be presented with a musical staff and a selection of instruments.
3. Use the mouse or stylus to click on the desired notes and instruments to create your melody.
4. You can also use the buttons at the bottom of the screen to control the tempo and volume of your composition.
5. When you are finished, you can save your composition and play it back using the buttons at the top of the screen.
Here are some additional tips for using Mario Paint Composer:
* You can use the "Copy" and "Paste" buttons to duplicate sections of your composition.
* You can use the "Undo" button to undo your last action.
* You can use the "Redo" button to redo your last action.
* You can use the "Save" button to save your composition to a file.
* You can use the "Load" button to load a saved composition.
* You can use the "Play" button to play back your composition.