We have loved exploring the ways in which pitch is created on musical instruments as part of our Sound Topic, in Science. We learned how the length of keys affects pitch on percussion instruments; the longer the key, the lower the pitch.
We also learned that notes on a guitar are affected by the thickness of the strings. The thicker the string, the lower the pitch. We were even able to control the pitch on an elastic band, depending on how far we stretched it.
It was a lot of fun.