Here is the link to her blog post: http://teachingmama.org/water-xylophone/
I already had Mason jars sitting in my kitchen. I filled them up with water (different depths) and got out the food coloring. That is literally all you need to do this fun activity :)
Here are the pictures :)
I had 5 available jars and only 4 colors of food coloring. So I mixed the blue and red to make a purple. This became a discussion on mixing colors for LO along with the actual music discussion that I had planned. :) I love when that happens!