Friction Harp

This instrument has 12 tones, the lowest note is the “G” at the top of the treble clef, and that rod is nearly 12 feet long. It is very much a soprano instrument, despite its size, in the same range that most people can whistle. Because the high notes can be painfully high, Tom began to look for ways to lower the range of the instrument.

To get another octave lower, you would need to have an aluminum rod 24 feet long… and to support its own weight, you’d probably have to use a rod with an inch and a half diameter. That’s a custom order job from an aluminum foundry that’s going to cost a lot of money, not to mention shipping. While it may be possible to weld two 12 foot rods together, the instrument would still be too big to be practical.

Looking at other materials was the logical course. When his daughter needed a project for her 8th grade science class, they worked together to compare the pitches of longitudinal waves in a variety of metals. They obtained 3/8 inch diameter 6 foot rods made of stainless steel, copper, brass, bronze, and aluminum, and mounted them with thumb screws in a wooden board.