In our continuing series on jazz improvisation I would like to discuss the application of certain scales, in addition to the usual major and minor, which will add spice to your solos by incorporating non-diatonic sounds usually associated with the dominant (V) harmony. In jazz this harmony is referred to as the “altered dominant” or “alt” for short and would contain as many as four possible altered tones (b5, #5, b9 and #9). This sound is very important in jazz harmony as it adds a great deal of color and gives the soloist much more to work with in terms of note choices.
I am assuming most everyone is familiar with the diatonic major scale as well as the seven modes derived from it. Just in case, a brief review may be helpful.
The seven modes are as follows:
- Ionian (major) C-D-E-F-G-A-B-C (I-tonic Major) Associate with Major7 chord.
- Dorian D-E-F-G-A-B-C-D (ii-supertonic minor) Associate with minor7 chord.
- Phrygian E-F-G-A-B-C-D-E (iii-mediant minor) Associate with minor7 chord.
- Lydian F-G-A-B-C-D-E-F (IV-subdominant Major) Associate with Major7 chord.
- Mixolydian G-A-B-C-D-E-F-G (V-dominant Major) Associate with Dominant7 chord.
- Aeolian (minor) A-B-C-D-E-F-G-A (vi-submediant minor) Associate with minor7 chord.
- Locrian B-C-D-E-F-G-A-B (vii-leading-tone diminished) Associate with minor7b5 chord.
Each of the seven modes is associated with each of the corresponding diatonic seventh chords that are generated from the diatonic scale. The association is strong because the notes that make up each seventh chord appear on every other note of the scale. For example, if we take every other note of the first mode (Ionian) we have the tones C-E-G-B which spells the C Major7 chord. These tones would naturally be emphasized as they would occur on the strong beats when playing eighth-notes. This chord/scale association does not require that the notes of the chord occur always on strong beats. As long as the chord tones are present within the scale an association with the chord sound exists. What occurs between the chord tones (passing tones) is less critical. We could generate any number of different scales including pentatonic, octatonic, chromatic and various synthetic patterns that contain the chord tones we are improvising over and achieve a successful result. Our ears are accustomed though to the traditional diatonic sounds of the modes described above so we will use these first. In theory then, you would play each mode over each of the corresponding chords in a tune. Although I am not a strong proponent of the modal approach to improvising, it is important to understand the function of these modes.
These scales are excellent for soloing over most changes in the typical jazz standard as long as the chords involved are diatonic seventh, ninth, eleventh and thirteenth chords. The limitation of these scales occurs when we encounter altered chords. As stated earlier, altered chords contain tones that are not part of the diatonic scale (b5, #5, b9 and #9 in major keys for example) that are commonly added to the dominant (V) chord. This is quite common in jazz as an over use of diatonic harmony is undesirable. So, what do we do when we encounter these altered chords in a tune? The most common technique is to use modes derived from the harmonic and melodic minor scales.
Let’s review these two scales as they would be constructed from the pitch A (or in A minor).
Harmonic minor: A-B-C-D-E-F-G#-A {minor (Aeolian) with raised seventh degree}
Melodic minor: A-B-C-D-E-F#-G#-A {minor (Aeolian) with raised sixth and seventh degrees} In jazz this scale is the same ascending and descending and is sometimes referred to as “jazz melodic minor” for that reason.
In the context of this discussion we will concern ourselves with only three modes of these scales that will work best and are commonly used over altered dominants: The fifth mode of harmonic minor and the fourth and seventh modes of melodic minor.
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Fifth Mode of Harmonic Minor (Phrygian Dominant)
The scale consists of the tones E-F-G#-A-B-C-D-E and is an excellent choice when playing over 7b9 and 7#5 chords. Again if we take every other scale degree we end up spelling the E7b9 chord (E-G#-B-D-F). So this chord sound would have a strong association with this scale as these notes would naturally be emphasized. The E7#5 (E-G#-B#-D) sound is also present with the inclusion of the note C (enharmonic B#). Of course both b9 and #5 could be included together in the chord as well: E7(#5)(b9). The best way to remember the correct choice of mode in this case is to play the harmonic minor scale that is built from the same pitch as your tonic chord, not the dominant chord as is sometimes incorrectly assumed. The mode begins on the dominant. For example:
E7(b9)(#5)-Play A harmonic minor from E to E (dominant).
A7(b9)(#5)-Play D harmonic minor from A to A (dominant).
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Fourth Mode of Melodic Minor (Lydian Dominant or Lydian Flat-Seven)
This scale contains the tones D-E-F#-G#-A-B-C-D and is an excellent choice for playing over 7b5 chords. In this case if we take every other note (strong beats) we end up with the unaltered D7 chord (D-F#-A-C). The b5 sound is still strongly implied with the inclusion of the G# (enharmonic Ab) in this scale. Personally, when using this mode I think of it as Mixolydian with a raised fourth. Since I already associate Mixolydian with dominant seventh chords it is easy to use my Mixolydian patterns that begin on the root tone of the altered dominant chord and just raise the fourth degree.
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Seventh Mode of Melodic Minor (Altered Dominant or Super Locrian)
This is the mother of all altered scales. The scale includes the notes G#-A-B-C-D-E-F#-G#. In jazz this is the number one choice for soloing over altered dominants because it contains all possible altered tones (b5, #5, b9 and #9) as well as the key elements of the dominant seventh chord associated with it (root, third and seventh). Let’s look at it in detail with its association with the G#7 chord in this case. The important chord tones G# (root) B# (enharmonic C or third) and F# (seventh) are present in the scale as well as all the altered tones: A (b9) B (#9) D (b5) and E (#5). An easy way to remember which is the correct choice of mode when playing over an altered dominant is to simply play the melodic minor scale that is a half-step above the root of the altered dominant in question. For example:
E7 (altered)-Play F melodic minor from E to E (seventh mode).
A7 (altered)-Play Bb melodic minor from A to A (seventh mode).
Not so hard to remember with a little practice.
I have included a pdf file below which summarizes the discussion. The filled note heads show passing tones (notes between chord tones) in the first set of seven diatonic modes. In the modes of harmonic and melodic minor the filled note heads indicate altered tones as well as unaltered passing tones. I am hoping this gives you some new and important scale sounds that will make your solos sound much more colorful and certainly more authentic.