This Is Your Brain on Music: The Science of a Human Obsession

by Daniel J. Levitin

From phylogenetic studies—studies of the brains of different animals up and down the genetic ladder—we’ve learned that the cerebellum is one of the oldest parts of the brain, evolutionarily speaking. In popular language, it has sometimes been referred to as the reptilian brain. Although it weighs only 10 percent as much as the rest of the brain, it contains 50 to 80 percent of the total number of neurons. The function of this oldest part of the brain is something that is crucial to music: timing. The cerebellum has traditionally been thought of as that part of the brain that guides movement. Most movements made by most animals have a repetitive, oscillatory quality. When we walk or run, we tend to do so at a more or less constant pace; our body settles into a gait and we maintain it. When fish swim or birds fly, they tend to flip their fins or flap their wings at a more or less constant rate. The cerebellum is involved in maintaining this rate, or gait. One of the hallmarks of Parkinson’s disease is difficulty walking, and we now know that cerebellar degeneration accompanies this disease.