Coffee Talk with Elmer Lewis: The Physics of Music – Without the Equations

Have you ever wondered why lower pitched instruments are larger than those that are higher pitched? Why ten violins are not twice as loud as five? And, why do several sound different – not just louder – than one? Other questions we’ll explore will include why wind instruments are louder and sound different than strings and why it matters in which key music is written?

To address such questions, we’ll use simple diagrams and graphs to show how sound wave amplitude, wavelength, and overtones determine how musical instruments work and how the brain processes sound to create our perceptions of loudness, pitch, and timbre.

While a nuclear engineer by profession, Elmer Lewis is a lifelong concert attendee fascinated by music, particularly as the bridge between science and the arts. He is Professor Emeritus and former Chairman of Northwestern University’s Department of Mechanical Engineering. His most recent book is Renewables or Nuclear, Which Should Lead in Curbing Climate Change? (Springer, 2026).