Overtone Series

A natural phenomenon in which a single pitch produces multiple additional harmonic pitches through mathematical divisions

The "Overtone Series", also known as the "Harmonic Series", refers to a sequence of harmonically related tones that are produced when a fundamental frequency is sounded. When a musical instrument or a sound source produces a tone, it is not just a pure single frequency but consists of a fundamental pitch along with a series of additional frequencies known as overtones or harmonics.

The Overtone Series is based on the physical properties of sound waves. When a musical instrument or a vibrating object produces a sound, it vibrates not only at its fundamental frequency but also at higher frequencies that are integer multiples of the fundamental frequency. For example, if the fundamental frequency is 110 Hz, the first overtone will be at 220 Hz (2 times the fundamental), the second overtone at 330 Hz (3 times the fundamental), the third overtone at 440 Hz (4 times the fundamental), and so on.

The Overtone Series forms the basis of the timbre or tone quality of a musical sound. The relative strengths and proportions of the overtones determine the unique sound characteristics of different instruments and voices. For example, a violin and a flute playing the same pitch will have different timbres because of the different amplitudes and distributions of their overtones.

In Western music theory, the Overtone Series has influenced concepts of harmony and chord structure. The fundamental frequency and its overtones form the basis of harmonic relationships and intervals. The relationship between the fundamental and the first overtone (octave) is considered the most consonant, while higher overtones introduce more complex and dissonant harmonies.

Musicians and composers often utilize the Overtone Series in various ways. They can explore harmonic relationships, create rich and complex textures, and manipulate the timbral qualities of sounds by emphasizing or suppressing specific overtones. Understanding the Overtone Series can enhance the understanding and appreciation of the harmonic and timbral aspects of music.

Example of Overtone Series

9. The Overtone Series and Timbre