What resonance means and the natural frequency of structures and objects, such as glass. A look at the effects of resonance, and some examples - why resonance is like swinging someone on a swing, attempts to shatter glass, using a professional resonator - a trained singer. The characteristics of sound, states of energy such as heat, light, sound are explained, along with technological application of sound waves, amplitude, wavelength, and frequency. Force, motion, and energy concepts such as resonance and vibrations and the ability of substances to transmit sound, and earthquakes and wave frequencies