Washtub Bass
 
            This homemade “cello” looks like one that townfolk may have used in the 1800’s and early 1900’s in America.  It is also very simple to construct.

To operate, adjust the lever back and forth while plucking the string to make different sounds.

The washtub base demonstrates the fact that different wavelengths produce different tones.  By moving the broom back and forth, you can change the tension on the string.  By changing the tension on the string, you change the wavelength traveling in the string and thus alter the sound.  The hollow washtub functions to amplify the sound of the string.  Unlike a formal stringed instrument, each of these instruments will be different and react to its own construction and player’s touch. 
Link to Bells Exhibit Page
Link to Construction Directions
Link to Sound Research Page
Link to MESA Equations Page
Link to MESA Home Page