The altered scale is a distinctive musical mode used primarily in jazz and contemporary music. It adds tension and color to improvisation and composition, making it a vital tool for musicians seeking complex harmonic textures. Understanding the altered scale involves exploring its structure, origins, practical applications, and common misconceptions.
Definition and Structure of the Altered Scale
The altered scale, also known as the altered dominant scale or the super Locrian scale, is a seven-note (heptatonic) scale derived from the melodic minor scale. It is characterized by a series of altered tones—most notably flattened fifths and flattened ninths—creating a dissonant, tense sound that resolves naturally to a tonic or target chord.
In terms of intervals, the altered scale can be viewed as a dominant scale with all possible alterations of the fifth and ninth degrees. Its formula, starting from the root, is:
- Root
- Minor second (♭2)
- Minor third (♭3)
- Major third (3)
- Flattened fifth (♭5)
- Minor sixth (♭6)
- Flattened seventh (♭7)
For example, in the key of C, the altered scale (C altered) consists of the notes: C, D♭, E♭, E, G♭, A♭, B♭. This scale contains the altered tones that generate tension, especially when used over dominant seventh chords with altered extensions.
Historical Context and Origin
The altered scale’s roots trace back to jazz improvisation and the development of modern harmony in the 20th century. It is closely related to the diminished and whole-tone scales, which also produce ambiguous or dissonant sounds. The term “altered scale” emerged as musicians sought a systematic way to describe the collection of altered tones that can be used over dominant chords to create tension before resolving.
Its theoretical foundation is linked to the concept of the “super Locrian” mode, which is the seventh mode of the melodic minor scale. The altered scale is essentially the Locrian mode with a raised fourth, giving it the characteristic dissonance that makes it unique among scales used in jazz improvisation.
In jazz theory, the altered scale became prominent with the advent of bebop and modal jazz, where improvisers began exploring more complex harmonic colors. It gained popularity through influential musicians like John Coltrane and Charlie Parker, who employed it to add expressive tension to their solos.
Practical Usage and Common Misconceptions
In practice, the altered scale is most often used over dominant chords that are functioning as V7 chords leading to a tonic. For example, when improvising over a G7 chord resolving to C major, a musician might choose the G altered scale to emphasize tension before resolution.
Common usage involves:
- Playing the altered scale over dominant seventh chords with alterations, such as G7♭9, G7♯9, G7♭13, or G7♯11.
- Using the scale to add chromatic color and tension in jazz improvisation.
- Resolving the tension created by altered tones to the chord tones of the tonic or target chord.
A frequent misconception is that the altered scale is only used for soloing; however, it also influences harmony and voicing choices in jazz arrangements. Another misconception is that it’s a “dissonant” or “unstable” scale—while it does contain dissonant intervals, its purpose is to create tension that resolves smoothly into consonance.
Musicians often learn the altered scale in relation to the melodic minor scale and practice it by substituting it over altered dominant chords, developing fluency through exercises and transposition. Its versatility makes it an essential element in jazz improvisation, especially in modern and modal jazz contexts.
In summary, the altered scale is a complex but highly valuable tool for musicians aiming to craft expressive, tension-filled solos. Its origins in jazz theory and its practical role in harmonic development continue to influence contemporary music improvisation today.
Related
- The 10 Different Types Of Trumpets You Should Know
- 21 Musical Instruments Of the Renaissance Period You Should Know
- The Different Types of French Horn: A Complete Guide for Musicians