Applet shows fundamental and first three overtones of a vibrating system. When the components and particles check boxes are cleared, the sum wave alone is shown. The particles check box option is provided to give a visual feel of the vibration. It can be cleared if it causes too much of clutter. This option can not be made when component checkbox is selected. When the components check box is selected, the frequency of the fundamental is shown in blue, the first overtone in green, the second in pink and the third in red. Sum of all the frequencies is shown in black.