Altered scales include one or more notes that is lowered or raised compared to its main variation. For example, Altered Locrian b4 that is identical to the Locrian Scale except for the flatted fourth.
Altered scales are in that way based on the same principles as altered chords. They are in most cases uncommon and much less used than the main versions.
The Altered Pentatonic is mostly used in jazz and deviate from both the Major and Minor Pentatonic in different ways. One special feature is the quadra-step interval between the first and second scale step.
Intervals: 1, b3, 3, b5, b6, 6, 7
Semi-notes: 1 - 4 - 2 - 2 - 3
Example of a scale, C Altered Pentatonic: C, Db, F, G, A, C.
The Super Locrian scale is also known as the Altered Scale but it should not be confused with the group of scales categorized as altered. The reason for the variation of the scale to include the word "Super" is because the scale is altered five times compared to the major scale. Compared to the Locrian scale, the fourth is flatted and that the reason for this scale also being called Altered Locrian b4.
Intervals: 1, 2b, 2#, 3, 5b, 5#, 7b
Semi-notes: 1 - 2 - 1 - 2 - 2 - 2 - 2
Example of a scale, C Super Locrian: C, Db, Eb, Fb, Gb, Ab, Bb, C
Lydian #2, Lydian #5 and Lydian b7 are three altered scales of the Lydian mode. The most common is the Lydian b7 (a.k.a. Lydian Dominant), but notice that Lydian #5 is relative to the Melodic Minor.
Example of a scale, C Lydian #2: C, D#, E, F#, G, A, B, C.
Example of a scale, C Lydian #5: C, D, E, F#, G#, A, B, C.
Altered Mixolydian Scale
In comparison with the Mixolydian scale does the Altered Mixolydian Scale include an extra note as well as a raised note. A raised fifth is added and also is the seventh raised.
Intervals: 1, 2, 3, 4, 5, 5#, 6, b7
Semi-notes: 2 - 2 - 1 - 2 - 1 - 1 - 2 - 1
Example of a scale, C Altered Mixolydian: C, D, E, F, G, G#, A, B, C.
Dorian b2, Dorian #4 and Dorian b5 are all examples of altered scales and in this case alternative versions of the Dorian Scale.
Example of a scale, C Dorian b2: C Db Eb F G A Bb C
In comparison with the Phrygian is the fourth note in the scale lowered in the Phrygian b4.
Intervals: 1, b2, b3, b4, 5, b6, b7
Semi-notes: 1 - 2 - 1 - 3 - 1 - 2 - 2
Example of a scale, C Phrygian b4: C, Db, Eb, Fb, G, Ab, Bb, C
|A Phrygian b4||A||Bb||C||Db||E||F||G|
In comparison with the Aeolian is the first note in the scale lowered in the altered Aeolian. C Aeolian b1 is almost identical with C# Aeolian (in which C is the tonic).
Intervals: 1b, 2, b3, 4, 5, b6, b7
Semi-notes: 3 - 1 - 2 - 2 - 1 - 2 - 1
Example of a scale, C Aeolian b1: C D# E F# G# A B C
|Ab Aeolian b1||Ab||B||C||D||E||F||G|
In comparison with the Ionian scale is the fifth raised in the altered Ionian scale.
Intervals: 1, 2, 3, 4, 5#, 6, 7
Semi-notes: 2 - 2 - 1 - 3 - 1 - 2 - 1
Example of a scale, C Altered Ionian #5: C, D, E, F, G#, A, B, C
Other altered scales
More examples of altered scales:
- Major b6 Scale
- Mixolydian b6
- Locrian bb7
- Super Locrian bb7
The presented material doesn’t include all scale alterations that can be found, but the excluded ones are in most cases to be considered as extraneous.