A Pan Flute. Shorter pipes produce higher frequency sound waves and a higher pitch. Good activity when you teach a unit on sound. The link gives you exact measurements to make notes in a true scale so you can play songs. The shortest straw must be exactly half the length of the longest straw.
have the student work together to pitch a tent in the classroom. afterward assign a process essay: "how to pitch a tent." leave the tent up for dramatic play- but put "campfire" on the floor with camp stools instead. Battery lanterns in the tent are a big hit too :)