Pentatonic and Blue scale
A pentatonic scale is a musical scale with five notes per octave derived from a standard major or minor scale. It’s commonly used in rock, blues, jazz, folk, and traditional music.
Why exist, why certain notes are omitted, why so interesting…
The Major pentatonic scale, derived from the Major scale, omits the 4th and 7th notes to create a smooth, consonant, and uplifting sound. This omission avoids the tension of the half steps between the 3rd and 4th, and the 7th and root, which can feel unstable or unresolved. An example is Bob Dylan's "Knocking on Heaven’s Door" where the vocal melody follows the G Major pentatonic scale: G, A, B, D, E.
The Minor pentatonic scale, derived from the Minor scale, omits the 2nd and 6th notes to create a darker, bluesy quality ideal for rock, blues, and emotive solos. Removing the 2nd, which feel unresolved, and the 6th, which leans toward the major scale, enhances the scale's emotional expression. An example is Led Zeppelin's "Stairway to Heaven" where the guitar solo primarily uses the A Minor pentatonic scale: A, C, D, E, G.
The pentatonic scale is simple and versatile, making improvisation easy. The Major pentatonic creates uplifting melodies, while the Minor pentatonic adds a bluesy feel. Adding a flat 5th "blue note" to the Minor pentatonic enhances its sound. This mix of simplicity and creativity makes the pentatonic scale appealing to musicians of all levels.
Blue scale
The blues scale is an adaptation of the pentatonic scale, incorporating an additional "blue note" to create its distinctive sound. While the pentatonic scale consists of five notes, the blues scale adds a flat 5th to introduce a more expressive, soulful tone. For instance, in the key of C, the C Minor pentatonic scale includes the notes C, E♭, F, G, and B♭, by adding a flat 5th, in this case G♭, we create the C blues scale includes C, E♭, F, F♯ (G♭) , G, and B♭.
The flat 5th (diminished 5th or augmented 4th) is added to create dissonance that naturally resolves, adding tension, expressiveness, and emotional depth. This gives the blues scale its unique flavor, common in blues, jazz, and rock music.
