Scales are named according to the tonality and function of the notes included. Types of scale include major, minor (natural, harmonic and melodic), chromatic, blues, pentatonic, whole tone and diminished. Although other scales exist, this article focuses on western musical systems and conventions.
ll major and natural minor scales relate to a specific key signature. These scales consist of the notes inside their respective key signatures. You can identify the notes by following a sequence from the twelve-note chromatic scale. The space between C natural and C# is a semi-tone (S) and two semi-tones make a tone (T). Thus, the space between C natural and D natural is a tone. All major scales follow the same pattern of T-T-S-T-T-T-S. By following this pattern from any note, you will sound the major scale and all the notes of its key signature. In C major, the notes are C, D, E, F, G, A, B and return to a higher C. Thus, if musical accompanists are in the key of C major, the soloist can use any of these notes without clashing.
Blues and pentatonic scales don't specifically fit one particular key signature or tonality but instead give a certain sound or flavor. These scales consist of fewer notes, making them more diverse. Nearly all blues soloing centers around the blues scale, which includes the “blues note,” flattened third, flattened fifth, and flattened seventh scale notes. This gives the melodic line the bluesy sound and defines this scale and genre. Nearly all rock guitar solos center around the pentatonic scale for the same reason.
It is easier to describe scales like the pentatonic scale by giving a numerical value to each note of the scale. For example, the notes in a C major scale are: C=1st, D=2nd, E=3rd, F=4th, G=5th, A=6th, B=7th. The C above is the octave or 1st. With this in mind, you can begin constructing scales in relation to their numerical quality. For example the minor pentatonic scales consists of 1st, flattened 3rd, 4th, 5th and flattened 7th. Flattening a note means reducing its pitch by a semi-tone and is expressed by the symbol; “b.” Thus, a C minor pentatonic is made up of C, Eb, F, G and Bb.
Discover what you can do with a C minor pentatonic scale. Notice that C, Eb, F, G, and Bb are all present in the tonality of Eb major. By applying the T-T-S system to the note Eb, you’ll find that all the notes of C minor pentatonic will appear, including some others. Therefore, if you are soloing over Eb major tonality, C minor pentatonic will be in tune.
Western civilization has an established musical system that underpins most music produced in the west. However, other musical cultures have alternative scales. What differs is the selection of notes that the scales comprise. In western music, there is nothing smaller than a semi-tone and the system starts again at a higher register after 12 notes. In contrast, Indian music contains micro-tones, the sound between two notes a semi-tone apart, or C and D#. Additional notes in the pitch inventory allow for a variety of scales quite different that the more familiar scales of western music.