We're starting to figure out this sound stuff by starting at the source! Using some car speakers, we began to feel vibrations when we played various genres of music at different volumes.
We know that instruments are related to speakers, so we asked our music teacher to borrow some instruments and see what happens as they're played. We agreed (even after watching some slow-motion videos) that all speakers and the instruments move back and forth in some way.
This lead us to co-construct a model for how a drum moves as the vibrations create sound.