Charles Wheatstone was born on February 6, 1802, at the Manor House, Barnwood, near Gloucester, England, and died in Paris, France, on October 19, 1875. His father, William, was in business as a shoe maker in Gloucester but he also taught music and several members of the family made musical instruments. On the death of an uncle, Charles and his older brother inherited the uncle's musical instrument manufacturing business in London. Although a competent businessman, he much preferred to give his attention to understanding the basic physics of music and musical instruments. He enjoyed the delicate work of designing and manufacturing musical instruments, and he devised new ones, in particular the highly successful concertina, patented in 1827.

Wheatstone's research into the physics of music addressed two practical questions. What is the difference between the sound vibrations of two notes having the same pitch but different timbre such as the...