Summer is all about catching waves, right? Check out these two videos about some crazy art that can be made with sound waves.
The first works because the video camera recording the water is recording at 24 frames per second. When the sound frequency slows down, it looks like the water is going backwards from the camera’s perspective.
The second video is a woman singing and how salt on a plate moves based on the frequency of the note/how the sound waves hit the salt. Keep watching until :40.