The basic principles of sound and its interesting features are introduced here. When the speaker of the Standing Waves exhibit causes the air to vibrate, the foam beads in the tube dance gracefully with the music and demonstrates the peaks of the waves. When the frequency of the sound happens to coincide with that of the Dancing Rings, resonance will occur and make the rings dance. You can even compose a piece of amazing Magic Music by simply waving your hands above an electronic circuitry and changing its oscillation frequency.