You will need to download Audacity to the student computers. It is for free on download.com. You will need to play with this program a little before you use it in the classroom so you are familiar with it.
Follow the directions on the lesson plan. Students will take an mp3 song (you will have to download or use one that you already have) and place it in audacity. Explain how to use and ask questions about sound energy - volume and pitch. Ask about the sound waves and which direction they are. Students can also sing into microphone and add their own voice. It is a fun extension to what we have already learned. My students loved it and their favorite part is where they increase the pitch and hear chipmunks voices! :)