One of my favorite movies is Miss Congeniality! If you have not seen it, number one, you should, but it is about an FBI agent who goes undercover in the Miss United States Pageant. Because she is not by any means a pageant star, for the talent portion she shows off her amazing skills playing music on different types of wine glasses. The reason sound is produced as she swirls her fingertip around the glasses is due to the principal called resonance. Resonance occurs when a system vibrates another system with natural frequency. Different size and shaped glasses cause differences in pitch because the sound wave vibrate differently due to their differing frequency. Nothing better than coming across some physics in one of your favorite films.