Many instruments produce sound by vibrating a string, or a column of air inside a tube. 

In this activity, Phil’s daughter, Sarah, shows you how instruments vibrate in fractions called the harmonic series.  You will see and hear these harmonics on a string (i.e., violin), an open-end tube (i.e., her trumpet), and a closed-end tube (i.e., panpipes).  She also includes four of her favorite bugle calls for you to play!