Harmonic Series Overview

What is the Harmonic Series?

Music comes from nature. The notes that we use can be traced to an acoustical phenomenon known as the harmonic series. Whenever a musical pitch vibrates, we name that pitch for its fundamental. The fundamental is the most prominent pitch. However, the source of the sound will also add acoustical impurities to it. Acoustic instruments create their sound by vibration, and in vibrating to one frequency they pass through many others. These other frequencies, or impurities, are actually other notes that can be heard faintly above the fundamental, and they are called overtones. The total sound of any note that you hear is a combination of all of these. We identify the note with a clear label, such as, “C”, but in reality it this is actually the note’s average pitch.

The overtones follow a pattern called the harmonic series. Each of these notes has a different sound because each instrument has a different timbre. The acoustic guitar and piano have different timbres because each instrument will strengthen different parts of the harmonic series.

Note: these musical relationships are approximate.

The Harmonic Series from C

These pitches are not exact because of differences between natural acoustics and the way manmade instruments are tuned.

The harmonic series always follows this pattern. The notes that are closest to the bottom are the strongest: a root, an octave, a fifth, another octave, and then a major third and another fifth. These are the strongest overtones, which makes sense: they form a major triad, the most famous chord in music.

Further up the series, we have a minor seventh, a root, a major second, a major third, an augmented fourth, a perfect fifth, a major sixth, a minor seventh and a major seventh.

Some tones are not present in the harmonic series. For instance, there’s no minor third and there’s no perfect fourth. The presence of other intervals implies these, though: the perfect fifths imply perfect fourths (going down).

Application of the Harmonic Series

The harmonic series can be used to understand some aspects of harmony itself (why certain notes fit together well), as well as why some instruments have a better tone than others. A human voice singing the note "C" and a guitar playing it will sound very different. This difference is called timbre. The harmonic series results in one of the major contributors of different timbres. If you play a note on the guitar, the instrument itself will tend to emphasize or amplify certain harmonics more than another instrument would. And the result is a different sound. If you listen to a monotone generated by a computer (such as a phone dial tone) and compare it to the same note played on your guitar, the guitar note will tend to sound much fuller and richer due to additional harmonics. And those harmonics are actually microscopic fragments of other notes mixed into the main note. If you amplified the harmonics enough the whole thing would sound terrible. A little goals a long way. This is commonplace in aesthetics; a little salt is good. Too much and you’ve ruined the dish.

Listening Example

Because each of the overtoneIn the harmonic series, an overtone is any note other than the fundamental. Overtones add subtle coloring to every note, but most of them are not audible by themselves.s are increasingly distant, you will not really hear them as actual notes; just as little pollutants that add color to the fundamentalIn the harmonic series, the fundamental is the lowest note, or the “actual note” played, whereas all other notes in the series are incidental consequences of playing the fundamental.. However, just to hear what they would sound like if they were played as real notes, we made this audio example.

The audio example starts with just the root or fundamental, and then you will hear each of the overtones. These are pitch-altered so that they match those of the harmonic series. And underneath each overtone we will play the fundamental in the bass for comparison.

Key Task

Memorize the approximate harmonic series:

R, R, 5, R, 3, 5, ♭7, R, 9, 3, ♯4, 5, 6, ♭7, 7, R

Go ahead, memorize it. It’s great for conversations with strangers.

As the creator of Hub Guitar, Grey has compiled hundreds of guitar lessons, written several books, and filmed hundreds of video lessons. He teaches private lessons in his Boston studio, as well as via video chat through TakeLessons.