One important aspect of jazz is its use of many complementary scales and the modification of these scales by the introduction of blue notes. In addition to the scales of Western European classical music, diminished and pentatonic scales are very important.

Two pentatonic scales common to jazz are the major pentatonic scale and the minor pentatonic scale.

The major pentatonic scale begins with a major scale and omits the fourth and the seventh scale degrees: a C major scale is {C, D, E, F, G, A, B}, so a C major pentatonic scale would be {C, D, E, G, A}:

The minor pentatonic scale could more accurately be called a mode, as it comprises the same notes as the major pentatonic scale, but begins on the sixth scale degree of the corresponding major scale. Continuing the example above, A is the sixth scale degree of C major, so the A minor pentatonic scale would be {A, C, D, E, G}:

The nomenclature, "minor pentatonic scale," is confusing, since this scale is actually constructed from a major scale; the term minor is employed in the sense of relative key, as the diatonic A minor scale is the relative minor of the diatonic C major scale.

The minor pentatonic scale with a flattened fifth, the fourth degree, is sometimes called the blues scale, on A {A, C, D, Eb, G}: