Scholastic
Scholastic: Dirtmeister's Science Lab: Good Vibrations
An experiment that explores the relationship between vibrations and pitch. This site includes web links, a challenge question, and notes to the teacher.
Other
Manchester Museum of Science and Industry: Sound 101: Bad Vibes
Learn about sounds and rate sounds from just "bad" to "really horrible." Then read an explanation about acoustics and the reason why people find some sounds to be worse than others. Also learn to mix your own sounds.
Scholastic
Scholastic Instructor: Science of Sound
This resource is for teachers who are looking for information, activities, experiments, and more pertaining to the science of sound.