Guitar Scales


A musical scale is a series of notes that are played in succession. In the case of guitar scales, rather than individual notes, the guitarist plays a series of chords in succession. Understanding the underlying principles of scales can assist a guitarist in his or her ability to both play and write music, as well as increasing the knowledge of musical theory possessed by the guitarist.

In Western music, there are three types of scales based on the intervals between the notes: chromatic, diatonic, and whole tone. Additionally, there are pentatonic, hexatonic, and heptatonic scales, which are defined by the number of different pitch classes in each. Respectively, these are scales with five, six, and seven different pitch classes, or tones. Outside of Western music, an enormous number of other scales exist, but most guitarists will be concerned primarily with the details of Western music.

The chromatic scale consists of all twelve notes of the Western scale, and all other scales are subsets of the chromatic scale. There is only a half-step between each of the tones of the chromatic scale. If you picture a piano keyboard, the chromatic scale would play through a complete sequence of seven white keys and five black keys, in the order in which they are found on the keyboard. While the chromatic scale is the most complete sort of scale, it is not widely used in music, as it lacks a harmonic direction.

Diatonic scales are heptatonic scales, consisting of seven notes, with a combination of whole tones and half-steps between each note. Continuing the piano keyboard visualization, a diatonic scale would use only the seven white keys. Another good example of a diatonic scale is the traditional "do-re-mi" sequence of notes, with which nearly everyone is familiar. Although this scale repeats the first note at the end, for a total of eight notes, the basic idea is still consistent with the seven note structure of a diatonic and heptatonic scale, as there are only seven unique notes. The eighth note is simply a repetition of the first note, one octave higher. The exact placement of the whole tones and half-steps within a diatonic scale varies between different scales. For example, the normal pattern for a major diatonic scale is that the first two notes will be a whole tone apart, while the third note is a half-step above the second. The fourth through six notes are again a whole tone apart, and the seventh and final note is a half-step above the sixth.

There are only two different whole tone scales, both of which are hexatonic scales of six notes each. Between the two whole tone scales, each of the notes from the chromatic scale is used only once. The notes are, as is probably apparent by the name, each separated by a whole tone. The two whole tone scales are C-D-E-F#-G#-A#, and B-Db-Eb-F-G-A. The sound of either of these two whole tone scales can be described as "dreamy," and one or the other is often used to signify a dream sequence in a movie.

With the basic information on scales in mind, how can a guitarist make use of this knowledge to assist them in playing and writing music?

By being familiar with a wide range of scales, a guitarist will know what notes work well in conjunction with one another. This skill is invaluable for those guitarists who also write music, as they can start with a chord that they wish to use, and determine which other chords will work best with that one, based on their knowledge of scales. Additionally, knowledge of scales can help a guitarist to improvise music, again operating on this same principle of knowing which notes and chords best fit with other notes and chords. Many musicians will refer to this as playing something "in the key of" a note.

A guitarist who is familiar with scales will also have a much easier time transposing music from one key to another key. Knowing what chords are a part of two scales, one of which contains the original key, and the other of which contains the intended key, allows the musician to make comparisons between the two and replace the original chords with the appropriate new chords.

While scales are a somewhat complex concept for a new musician to grasp, particularly when considered more extensively than within the scope of this article, it is certainly worthwhile for a guitarist to achieve at least basic knowledge of the topic. With the benefits to song writing and improvisation that such knowledge can provide, a guitarist is able to create their own music, rather than be limited by music that has already been written by others.