The Altered Scale: Your Ultimate Guide to Jazz Dominant Tension

What is the Altered Scale?

Imagine a dominant chord that's not just pushing to resolve, but is practically screaming to. That's the sound of the altered scale. It's a collection of notes specifically chosen to create friction and intensity over a dominant 7th chord (like G7). While it sounds complex, its construction is beautifully logical. At its core, the altered scale is simply the 7th mode of the melodic minor scale. This connection is the key to mastering it quickly.

Scale Construction and Formula

The altered scale is built on a simple premise: keep the essential guide tones (the 3rd and b7th) of a dominant chord and alter everything else. The most common formula, using C as the root, is:

Formula: Root - b9 - #9 - 3 - #11 - b13 - b7

Let's look at the C Altered scale. Its notes are C (Root), Db (b9), D# (#9), E (3), F# (#11), G# (b13), and Bb (b7). Notice it contains both a "lowered 9th" and a "raised 9th," creating a rich, dissonant color.

C Altered Scale (with Scale Degrees)

The notes of the C Altered scale, labeled with their function relative to the root C.

The Secret Shortcut: The Melodic Minor Connection

This is the most important concept for learning this scale. The altered scale is the seventh mode of the melodic minor scale. This means to find the altered scale for any dominant chord, you simply play the melodic minor scale starting a half step above the root of the chord.

Example: To play a C Altered scale (for a C7alt chord) , you play a Db Melodic Minor scale. The notes are identical, just the starting point and harmonic context are different.

Db Melodic Minor Scale vs. C Altered Scale

Listen and see how the notes are identical. The first measure is Db Melodic Minor. The second is the C Altered scale, which starts on the 7th note of Db Melodic Minor.

Practical Application: The ii-V-I Progression

The most common place you'll use the altered scale is over the V chord in a minor ii-V-i progression (like Dm7b5 - G7alt - Cm7) . It's also frequently used in major key ii-V-I progressions for a more "outside" sound, especially when the V chord is explicitly marked as "alt". Here is a sample lick over a G7alt chord resolving to C minor.

Voice Leading and Resolution

The power of the altered scale lies in how its tense notes resolve. Each altered tension has a strong tendency to move to a stable chord tone of the tonic chord. Understanding this movement is key to making your lines sound logical and musical, not just random.

• The b9 resolves down a half step to the root of the tonic. (e.g., Ab over G7alt resolves to G on a C major tonic, or the 5th of a C minor tonic) .
• The #9 resolves up a half step to the minor 3rd of the tonic. (e.g., A# over G7alt resolves to B on a C major tonic, or down to the root G of a C minor tonic).
• The #11 resolves down a half step to the 5th of the tonic. (e.g., C# over G7alt resolves to C, the root of a C major or minor tonic).
• The b13 resolves down a half step to the major 3rd of the tonic (or the root). (e.g., Eb over G7alt resolves to E on a C major tonic, or stays as the minor 3rd of a C minor tonic).

Practice Strategies

Mastering the altered scale isn't just about memorizing the notes; it's about internalizing its sound and feel. Here are some effective practice strategies:

1. Think Melodic Minor: Drill the melodic minor scale in all 12 keys. Then, for any V7 chord, practice playing the melodic minor scale a half step up. (For G7, practice Ab melodic minor) .
2. Sing It: Sing the scale over a drone of the root or a V7 chord. This connects your ear to the theory.
3. Pattern Practice: Play the scale in thirds, fourths, and simple 1-2-3-5 patterns. This breaks you out of simply running the scale up and down.
4. Apply to Standards: Take a jazz standard you know, like "Autumn Leaves" or "All The Things You Are." Isolate every V7 chord and practice improvising over it using only the altered scale. Record yourself and listen back.

Deeper Connections and Fun Facts

The altered scale has some interesting hidden structures. It's sometimes nicknamed the "diminished whole-tone" scale. Why? Because the bottom half of the scale (from the root: R, b9, #9, 3) resembles a diminished pattern, while the top half (3, #11, b13, b7) resembles a whole-tone scale pattern. Bebop pioneers like Charlie Parker and Dizzy Gillespie intuitively played these altered notes long before the scale was formally named and codified by theorists like George Russell in his "Lydian Chromatic Concept."

Conclusion

The altered scale is more than just a collection of dissonant notes; it's a fundamental tool for expressing the tension and release that defines so much of the jazz language. It unlocks the sound of modern harmony and gives improvisers a reliable, systematic way to navigate altered dominant chords. While it may seem intimidating at first, understanding its connection to the melodic minor scale makes it surprisingly accessible. Start slow, integrate it into tunes you already know, and listen for it in the solos of your favorite jazz masters. Before long, this "ultimate" dominant scale will become an essential part of your own musical voice.

References:

1. Levine, Mark. (1995). The Jazz Theory Book. Sher Music Co.

2. Russell, George. (2001). George Russell's Lydian Chromatic Concept of Tonal Organization. Concept Publishing Company.

3. Aebersold, Jamey. (1992). Volume 57 - Minor Blues In All Keys. Jamey Aebersold Jazz.

4. Coker, Jerry. (1997). Jerry Coker's Jazz Keyboard. Alfred Music.