Definition of the Blues Scale
The blues scale is a hexatonic scale commonly used in blues, jazz, rock, and related genres. It derives from the minor pentatonic scale by adding a flattened fifth, known as the 'blue note,' which creates tension and emotional depth. This scale typically consists of six notes and is characterized by its ability to convey melancholy and expressiveness in melodies.
Structure and Key Components
The blues scale follows a specific interval pattern: root, minor third, fourth, flattened fifth (or augmented fourth), fifth, and minor seventh. For example, in the key of C minor blues scale, the notes are C, E♭, F, F♯/G♭, G, and B♭. The flattened fifth introduces a dissonant 'bent' quality, mimicking vocal inflections in blues singing, and is a core element distinguishing it from other scales.
Practical Example: Blues Scale in C
Consider a simple guitar riff using the C blues scale: starting on the root C, ascending to E♭ (minor third), then F (perfect fourth), bending to F♯ (blue note), resolving to G (perfect fifth), and ending on B♭ (minor seventh) before returning to C. This sequence, often played over a I-IV-V chord progression like C-F-G, forms the basis of many blues solos, such as those in B.B. King's style.
Importance and Applications in Music
The blues scale is foundational to blues improvisation and influences genres like jazz, rock, and soul. It allows musicians to navigate chord changes fluidly while emphasizing emotional expression through the blue note. In education, learning the blues scale builds skills in scale construction, improvisation, and understanding modal harmony, making it a staple in music theory curricula for aspiring performers and composers.