Overview of Pentatonic Scales in Music Theory

Piano keys

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The word "pentatonic" comes from the Greek word pente meaning five and tonic meaning tone. Simply put, the pentatonic scale consists of five notes within one octave, which is why it is also sometimes referred to as a five-tone scale or five-note scale. The major pentatonic scale also gets its name from being five notes out of the seven notes from the major scale while the minor pentatonic scale has five notes from the minor pentatonic scale.

Pentatonic scales tend to sound good despite random orders due to the absence of dissonant intervals between them. This is one of the most commonly used scales for rock and guitar music due to its great sound during chord changes in a key. One can locate the pentatonic scale easily with a piano by simply pressing the black notes.

Ancient History and Pentatonic Scales in Music

It is believed that the pentatonic scale was used way back in ancient times. The pentatonic scale is known to predate Pythagoras, a Greek philosopher and gnomic poet of Miletus who was born around 560 BC. Historical musical instruments such as bone flutes were made out of the bones of birds, likely due to the hollow bones of birds for sound. These musical instruments were found to be tuned to the pentatonic scale, with the theory that they are about 50,000 years old.

The number five is important in relation to ancient history due to several interesting facts:

  • The number five was considered the "number of man." During ancient times, artists like Leonardo da Vinci illustrated this type of five-pointed stance in his work, "Vitruvian Man."
  • Pythagoras and the Pythagoreans wore pentacle shaped jewelry with words like "health" on it, translated from Greek.
  • The forming tones of the pentatonic scale were derived from a concept of the solar system and its five planets by Pythagoras in his theory called "Music of the Spheres."

Major and Minor Pentatonic Scales

The two basic forms of pentatonic scales are major and minor. The major scale consists of the first - second - third - fifth - sixth notes of a major scale.

The minor notes consist of the same five notes of a major pentatonic scale but its tonic (first note of the scale) is three semitones below the tonic of the major pentatonic scale. For example, the C major pentatonic (C - D - E - G - A) has the same notes as the A minor pentatonic (A - C - D - E - G) but arranged differently. The first note or tonic of the A minor pentatonic scale (=A) is three semitones (half steps) lower than the first note of the C major pentatonic scale (=C). It uses the first - minor third - fourth - fifth - minor seventh notes of a scale.

Composers like Claude Debussy have used pentatonic scales for added effect in his music. The anhemitonic form of a pentatonic scale has no semitones (ex. c–d–e–g–a–c) and this is the most commonly used form.