In 1964 it seemed as if the avian vocal organ, the syrinx, was a good place to start understanding the relation between brain and song. I started with chaffinches. I found that an alarmed chaffinch, which had had the nerves to the syrinx cut, breathed with difficulty. This problem could be avoided if one cut only the right or left nerve to the syrinx. Song was distorted, but breathing was not. I denervated the left half of the syrinx in many chaffinches and made careful notes of how their song was distorted. Many months later, I operated on one chaffinch's right side. The song of this bird did not change!
After confirming this result I realized I had stumbled across one of those little gems we all dream of finding. Even though the chaffinch syrinx consists of two anatomically similar halves—each with its own air supply, muscular control and innervation— ...