| PIPES OF PAN demonstrates 
              how tubes of varying length act to select and amplify sound waves 
              of different frequencies. Ten glass tubes of different length filter 
              out specific tones from the ambient noise of the museum. Each pipe 
              is resonant at a certain frequency, which is determined by its length. 
              A visitor listening to each pipe in turn, from longest to shortest, 
              will hear a strange progression from low-pitched tones to higher 
              ones. |   |