Sound/Pitch Jars

HELLO!  We continue to learn about sound and sight!  Today we made Sound Jars and learned about pitch!  What causes pitch?  What is pitch?  Why is low and high?  What is a high pitch and a low pitch?  What are some examples?  We then predicted which jar would make the highest pitch and also the lowest pitch?  Why?  Finally, we were able to test out the sound jars with a ruler!