This Demonstration shows the differences in sound produced by open and closed pipes. After choosing an open or closed musical instrument, you can change the length of the air column within the pipe, which is represented by a blue rectangle, by using a slider showing the number of keys on the pipe being pressed. You can also determine the air temperature using the slider. After these are chosen, the Demonstration outputs the wavelength and frequency of the sound emitted from the pipe. Also, the audible sound that corresponds to this frequency can be played. Furthermore, it determines whether this frequency is in the audible range for humans. The purpose of our project is to show how the temperature and length of the air column within the pipe change the frequency and wavelength of the emitted pitch.
for an open pipe is given by
is the number of node-to-nodes or 1 for the fundamental frequency,
is the velocity of sound in air, and
is the length of the pipe. The frequency for a closed pipe is given by
. In either case, the corresponding wavelength is
The sound velocity is given by
is the air temperature. The audible range for a human is between 20 and 20,000 Hz.
Snapshot 1: shows an open pipe with the longest pipe length and the lowest temperature
Snapshot 2: shows an open pipe with the shortest pipe length and the highest temperature
Snapshot 3: shows a closed pipe with a medium pipe length and an intermediate temperature
 A. H. Benade, Fundamentals of Musical Acoustics
, New York: Oxford University Press, 1976.
 N. H. Fletcher and T. D. Rossing, The Physics of Musical Instruments
, 2nd ed., New York: Springer, 1998.