See the outdoor sound lesson for more sound activities (some loud and some need the space of outdoors).
Introduce the concept of sound with students making their own sound sandwich.
Help students figure out how the sound is made: the vibration of the elastic band is transmitted to molecules in the air, causing them to vibrate. This vibration of molecules travels through the air to our eardrum. In our ear the vibration is converted to a nerve signal that is sent to our brain, so we sense the vibration as a sound.
Use slinky to model how sound vibrations travel: Sound Vibration Model.
Explore the pitch of sound through sound with a ruler.
Show on a ukelele or other musical instrument how pitch can be changed by changing the length of a string/tube. Discuss other instruments that students play and how the pitch changes in them.
End with singing a class song using the instrument, students accompanying on their sound sandwich or duck caller.
Additional exploration of sound travelling through different materials with the sound through solids activity.
Note that the constant noise of this class builds the energy level of the students quite dramatically. Sound through string keeps things a bit less hectic as students' ears are blocked. Doing this lesson outdoors also a good option - see sound outside lesson plan.
Ruler vibrations too subtle/complex for younger grades - maybe switch out with elastic band sounds where they can see the vibration.
Stuff to try: http://science-notebook.com/sound01.html