Overtone

Harmonic partials on strings

File:Overtones Demo.ogg

Allowed and forbidden standing waves

Overtones (most properly numbered) of closed pipe

Flageolette

Rimsky-korsakov-overtone-chord-deomonstration

Overtone refers to any frequency in a sound that is higher than the fundamental frequency. Overtones are integral components of the harmonic series in music and acoustics, contributing to the timbre or color of a sound. The fundamental frequency, also known as the first harmonic, is the lowest frequency of a sound and determines its pitch. Overtones, or harmonics, are vibrations at frequencies that are multiples of the fundamental frequency. The presence and relative intensity of these overtones influence the character and quality of the sound.

Overview

When a musical instrument or any other resonant system vibrates, it does so not only at its fundamental frequency but also at higher frequencies known as overtones or harmonics. These overtones are mathematically related to the fundamental frequency, creating a series of pitches called the harmonic series. The first overtone is the second harmonic (twice the frequency of the fundamental), the second overtone is the third harmonic (three times the frequency of the fundamental), and so on. The terms "overtone" and "harmonic" are often used interchangeably, but they have distinct meanings. All harmonics are overtones, but not all overtones are harmonics. This distinction is important in understanding the complex nature of sound production and perception.

Physics of Overtones

The production of overtones can be explained by the principles of wave physics. When a string, air column, or other resonant system vibrates, it does so in segments as well as a whole. These segments produce higher frequencies alongside the fundamental frequency. The specific pattern and intensity of these overtones contribute to the timbral quality of the sound. In string instruments, for example, the length, tension, and material of the string influence the production of overtones. In wind instruments, the length of the air column and the method of tone production (e.g., reed, lip vibration) affect the overtone series.

Musical Implications

Overtones play a crucial role in music, affecting the tuning, timbre, and harmony of instruments and voices. The harmonic series is fundamental to the development of musical scales and chords. Musicians and instrument makers manipulate overtones through instrument design, playing technique, and vocal training to achieve desired sound qualities. Understanding and controlling overtones allows for the production of rich and complex sounds in musical performance.

Applications Beyond Music

The concept of overtones extends beyond music to other fields such as acoustics, electronics, and even quantum mechanics. In acoustics, the analysis of overtones helps in the design of spaces with desirable sound characteristics. In electronics, overtones are considered in the design of oscillators and signal processing. The principles underlying overtones in physical systems also find analogs in the quantized energy levels of atoms and molecules in quantum mechanics.

See Also

• Harmonic series (music)
• Timbre
• Pitch (music)
• Resonance
• Acoustics
• Musical acoustics