Bb altered

Construction

Step pattern (W = whole step, H = half step): H-W-H-W-W-W-W.

Formula (intervals from the root): 1-b2-b3-b4-b5-b6-b7.

Every degree except the root is flatted. Enharmonically (same pitch, different name), the b4 functions as the major 3rd, so the essential dominant chord tones are present: 1, 3 (enharmonic b4), and b7. Everything else is altered. This is the melodic minor family's most chromatic mode.

Origin and Relationships

The altered scale is a mode -- a scale derived by starting a parent scale from a different degree.

• Parent: the 7th mode of melodic minor. From the altered scale root, go up a half step to find the parent melodic minor (e.g., B altered shares the same notes as C melodic minor).
• Alternate names: Super Locrian, diminished whole tone, Ravel scale. The "diminished whole tone" name describes the scale's structure: the first four notes outline a diminished pattern, the last four outline a whole-tone pattern.
• Compare to Locrian: both share b2, b3, b5, b6, and b7, but Locrian has a natural 4 (minor function) where Altered has b4/enharmonic 3 (dominant function). That enharmonic major 3rd -- the same pitch heard as a different scale degree -- is the reason Altered works over dominant chords and Locrian does not.

Harmonic Context

In Roman numeral analysis (uppercase = major, lowercase = minor):

• 7alt (altered dominant): The home chord. Extensions (9ths, 11ths, 13ths) are chord tones beyond the basic 1-3-5-7. The altered scale provides b9, #9, #11 (enharmonic b5), and #5 (enharmonic b6) -- every possible dominant alteration.
• Common voicing pairs: b9 with #5 and #9 with b5 are the most frequently used combinations in jazz comping, giving two distinct altered colors from the same scale.
• V7alt to I (a cadence -- a chord sequence that creates a sense of arrival): The standard jazz resolution. Maximum chromatic tension resolving to consonance. The altered scale is the default vocabulary for this moment.
• Tritone sub link: The altered scale over V7 contains the same pitches as Lydian Dominant over bII7. This shared pitch set is what connects the altered dominant to the tritone substitution.

Characteristic Tones

The intervals that give the altered scale its distinctive sound:

• b9 and #9 (both ninths altered): Two altered ninths in one scale. The b9 creates tight dissonance against the root; the #9 (enharmonic b3) adds a bluesy edge. Together they generate maximum upper-structure tension.
• b5/#11 and #5/b6 (both fifths altered): No perfect 5th exists. The absence of a stable 5th keeps the chord restless and forward-leaning.
• b4/3 (enharmonic major third): The hidden dominant anchor. Without this enharmonic 3rd, the scale would be minor -- it is what separates Altered from Locrian and gives the scale its dominant function.

Melodic Applications

Use the altered scale over V7 chords when you want maximum tension before resolution. Target the 3rd (enharmonic b4) and b7 to keep the dominant function audible while the altered tones create dissonance around them. Over V7alt resolving to I, every chromatic tension snaps into consonance -- the more tension you build, the more satisfying the arrival.

Practice Seeds

Find the chord. Locate 1, 3 (enharmonic b4), and b7 within the scale. Hear how the dominant chord tones anchor the sound amid all the alterations -- this skeleton is what makes the scale functional over dominant chords.

Melodic minor connection. Play the melodic minor scale from a half step above the root, then play the same notes starting from the altered scale's root. Hear the parent-mode relationship -- same seven pitches, completely different tonal center and mood.

V7alt to I. Play the altered scale over a V7 chord, then resolve to Imaj7. Experience the tension-resolution payoff -- every chromatic note snaps to a chord tone on arrival.

Locrian comparison. Play Locrian and then Altered from the same root. Hear how the enharmonic major 3rd in Altered creates dominant pull where Locrian's natural 4 stays minor -- one degree, entirely different function.