6 Notes on the Rich Variety of Musical Scales

When children or adults learn music theory, one of the basic concepts they have to master is musical scales. A scale, simply put, consists of a graduated and organized set of tones that span and divide up an octave. By selecting a specific series of notes, as well as the intervals between them, a composer is setting up a pattern that he or she will use to express a full range of thought and emotion. 

Scales are at the core of musical keys. If, for example, a piano teacher refers to Ludwig van Beethoven’s “Moonlight Sonata” No. 14 in the key of C-sharp minor, the student will immediately understand that this particular classic work is built on the C-sharp minor scale. 

Check out the following list of interesting facts for more about the history of musical scales.
​

Just how many scales are there? ​

There are actually hundreds of musical scales that people around the world have used at one time or another. Musicologists, in fact, point out that—theoretically speaking— there is an almost infinite number of scales that can be formulated.
 
Historians of music observe that the scales that develop within individual cultures tend to provide a glimpse into those cultures, with the most basic and straightforward scales associated with early or pre-literate societies, and the more sophisticated scales working their way through later and more complex societies.
 

Doing the math

As an example of the possibilities of building scales, we can consider the fact that there are 12 major scales in the Western musical tradition, each built on one of the 12 distinct pitches in an octave.
 
But there are also 24 minor scales—12 melodic and 12 harmonic—and a further 72 additional modes, which are simply scales that start out on different pitches. The Dorian mode of the ancient world is one of these—it begins on the note of D and includes, as the C-major scale does, no sharps or flats. Ancient musicians similarly built the Phrygian mode on the note of E. In total, there are seven modes that can be made based on the seven notes in an octave.
 
Additionally, there are chromatic, diminished, blues, and other distinctive types of scales that have emerged over time and in a variety of cultures. 

​How scales are built

The common denominator is that nearly every known musical scale is built on the strengths of between six and eight individual notes (five to seven intervals). And the tones included in each scale typically also all display a frequency ratio connection to the very first tone of that scale. Students of guitar and piano will find that they can adapt most of the world’s known scales to be played on their versatile instruments.
 
With this wide-open ground for the development of scales, musicians in the traditions most familiar to Western audiences have developed and popularized only a relative handful. 

An ancient example that still rings true

Scholars believe that the pentatonic scale is among the oldest in the world. Based on five intervals dividing six notes, it can be found today incorporated in much of the music of the world. In its common anhemitonic form (meaning it contains no semitones), it consists of notes in the major scale at positions 1, 2, 3, 5, 6, and 8.
 
In the key of C-major, this would include the notes C, D, E, G, A, and back to C. This absence of half-steps gives the pentatonic scale a harmonious, immediately pleasing sound. Some of the music in the tradition of medieval Gregorian chant is based on the pentatonic scale. 
​

A distinctively American scale

The blues scale is, arguably, the one on which much of today’s popular music is based. Anchored in African-American popular music of the Southern United States in the 19th century, the blues scale began with the human voice, as everyday people composed working songs, folk songs, and more.
 
The blues scale is musically complex. Some experts believe it is based on six notes, while others say seven. Some even count as many as nine notes on the blues scale.
 
In general, however, music theorists believe that the blues scale is a different version of the traditional minor and major pentatonic scales. One way to turn a regular scale into a blues scale is by adding “blue” notes—commonly a flat fifth-degree on the scale that lies next to the natural fifth on that scale. For example, a blues scale built on a minor pentatonic scale might include the following note sequence: A, C, D, E-flat, E, G, A.
 
Great blues singers like Robert Johnson and Ma Rainey made this form familiar to listeners through early 20th-century recordings of their performances.
 

A rainbow of musical color

The word “chromatic,” derived from the Greek word chroma (color) immediately gives a clue to the sounds of the chromatic scale. The chromatic scale employs all 12 notes in the Western musical tradition, and proceeds from one semitone to the next, leaving out none of the half-tones in its climb up the sequential ladder. Thus, in the chromatic scale built on the note of C, the sequence would be C, C-sharp, D, D-sharp, E, F, F-sharp, G, G-sharp, A, A-sharp, B.
 
Many composers have used chromaticism to bring color to passages of larger works built on more traditional scales. This scale is particularly associated with the atonal and experimental music that came to prominence in the 20th century.
 
Composer Arnold Schoenberg achieved renown as the originator of the serial 12-tone row, based on the chromatic scale. This key-less method requires a piece of music to deploy all 12 tones in the scale equally often, and it achieves this goal by a systematic ordering of the 12 tones.