Twang is a graphical simulation of the harmonic motion of a vibrating string. The flickering line in the center is the string in question. To "pluck" the string, click on either of the double-arrow buttons at the top. You can hold the button down to create a longer disturbance in the string's vibration. (The center button stops & starts the vibrations)
The disturbance travels along the string and bounces off the top & bottom.
The string has no friction and will continue to vibrate until reset.
As you will see, plucking always gives a mixture of harmonics. For a more elegant look, you can plot pure or mixed harmonics. Simply enter up to three values in the fields at the bottom of the display, and click "Set Harmonics".
Values in the range [1-20] give the best looking waveforms. The harmonics are hard to recognize beyond about 50, and the pixel resolution gives a Nyquist frequency of this applet to be about 150. Above that frequency, harmonics cannot be correctly rendered on the screen.
"Twang" is based on the article "The Vibrating String - A Simulation of Motion" by William E. Bennett, published in the Creative Computer magazine, June 1980, pg. 114pp