This is a demonstration of the periodic variations in the sound loudness, or “beats,” produced by two frequencies that are close to each other, with the beat frequency given by the difference between these frequencies. The nearer the two frequencies, the slower the beats. Thus, musicians “tune out the beats” to tune their instruments to a reference frequency. It was created at Utah State University by Professor Boyd F. Edwards, assisted by James Coburn (demonstration specialist), David Evans (videography), and Rebecca Whitney (closed captions), with support from Jan Sojka, Physics Department Head, and Robert Wagner, Executive Vice Provost and Dean of Academic and Instructional Services.