Blues scale
The term blues scale refers to several different scales with differing numbers of pitches and related characteristics. A blues scale is often formed by the addition of an out-of-key "blue note" to an existing scale, notably the flat fifth addition to the minor pentatonic scale. However, the heptatonic blues scale can be considered a major scale with altered intervals.
Types[edit]
Hexatonic[edit]
The hexatonic, or six-note, blues scale consists of the minor pentatonic scale plus the ♭5th degree of the original heptatonic scale.[1][2][3] This added note can be spelled as either a ♭5 or a ♯4.