Literal "Rock" Tone

Here's another odd capture. A couple of weeks ago, I tried an experiment using expired pasta, rice, and other "Household Items" laid directly on an exposed speaker. As the speaker vibrated, these objects created this strange, broken fuzzy tone that honestly sounded way better than I expected. But it left me wondering... What other objects or substances could create an interesting guitar tone? So this time, I grabbed some river pebbles from the garage, larger stones from outside, and a few more random things lying around the house to create a very literal "Rock tone." Less Rocks More Rocks Different Rocks (larger stones) Cereal PVC Pipe And once again, the results were weird... but maybe weird in a useful way?