1. With the funnel, fill the bottles up with different amounts of water.
2. Tap each bottle with your spoon to see if you like the note it makes. Add more water to make a lower note and pour out some if you want a higher note.
3. Once you're satisfied with the notes, mark off the water level using the tape or marker. This will remind you how far to fill up the bottles later after water evaporates.
4. Find a place where you can play the piano. Make sure you can have an audience sit comfortably there if you want to play for people or that there's space for your friends to play their instruments with you.
5. Line the bottles up. Use an arrangement you like or try lining them up from lowest to highest tone.
6. (Optional)- Use the food coloring to color the water differently for each bottle. You might want to use the colors of the rainbow: Red, Orange, Yellow, Green, Blue, Indigo, Violet (add LOTS of blue dye), and then red again for the last note. That's ROY G BIV with an extra red for the last note.

Remember:
red + blue = purple
blue + yellow = green
red + yellow = orange

You're all set to play!