EQUIPMENT
    Organ Pipes
    Plexiglas Organ Pipe Box
   
  


NARRATIVE
            Several adjustable organ pipes are available. The pitch may be varied by sliding the plunger through the tube. The progression from low pitch to high pitch as the plunger is inserted is not uniform. At a certain point, the second harmonic dominates, doubling the pitch. The other two pipes are inserted in a box which is connected to compressed air. The variable length pipe may be adjusted to demonstrate beats due to the different frequencies of the two pipes.