Using Modes with ii-V-I (or i) Chords
First developed by the ancient Greeks, modes are an important musical element used to create melodies and improvise. Modes can be built on all seven pitches in the major scale. For example, the C major scale is also known as the Ionian mode since it's built on the first scale degree. Similarly, if you build a mode on the sixth scale degree in C major you will get an Aeolian mode or an A natural minor scale. Figure 15-11 shows all seven modes as derived from naturals or white keys on the piano presented in ascending order. Bear in mind that, at least as far as this book is concerned, the terms “mode” and “scale” are interchangeable.
As illustrated in Figure 15-11, the intervals in the Dorian mode are: whole, half, whole, whole, whole, half, whole. In C major, this becomes: D to E (whole), E to F (half), F to G (whole), G to A, (whole) A to B (whole), B to C (half), and C to D (whole).
The minor third and the major sixth intervals of the Dorian mode largely define this scale. All in all, the Dorian mode is really just a natural minor scale with a raised (major) sixth. In fact, the Dorian mode uses the same notes as the natural minor scale located a perfect fourth below or a perfect fifth above the mode's root. For example, the notes in an A minor scale (A, B, C, D, E, F, G) match those of a D Dorian mode (D, E, F, G, A, B, C). The only difference is the starting pitches.
The Dorian scale is typically used to play over minor chords that do not contain alterations (e.g., a flat five). For example, if you have a major ii-V-I chord progression, you will likely want to use the Dorian mode on the ii chord.
Lydian Dominant Scale
The Lydian dominant scale is the fourth mode of the melodic minor scale. In other words, it starts on the fourth scale degree of the melodic minor. Often, musicians look at the Lydian dominant as a hybrid of two scales. Specifically, it's seen as a synthesis of the Lydian mode, which is a major scale with a raised fourth, and the Mixolydian mode, which is a major scale with a flatted seventh; see Figure 15-11.
The Mixolydian mode is also similar to the bebop dominant scale. In fact, the only difference between these scales is the addition of a leading tone in the latter. This creates chromatic movement at the top end of the scale. See Figures 15-12 and Figure 15-13 for the bebop dominant scale and the Lydian dominant scale, respectively.
Bebop Dominant Scale Versus Lydian Dominant
On its own, the bebop dominant scale may be used over any V7 or dominant chord. However, the fourth scale degree can be problematic given the fact that the dominant chord contains a major third. If not handled properly, the perfect fourth of the scale can clash in a disagreeable manner with the third of the V7 chord. (This is especially true if your melody hangs on the fourth scale degree.) Therefore, composers and soloists either use this interval cautiously or they avoid it altogether. The other option is to use the Lydian dominant scale, which allows you do construct hip, modern sounding lines. Two examples of Lydian Dominant jazz lines are shown in Figures 15-14.
Figure 15-11: The seven basic modes
FIGURE 15-12: The bebop dominant scale
FIGURE 15-13: The Lydian dominant scale
FIGURE 15-14: Lydian dominant jazz lines
In summary, sensible scalar options for a straightforward major ii-V-I chord progression becomes the Dorian, Lydian, Dominant, and Lydian modes, respectively; see Figure 15-15. This assumes you wish to sound “contemporary.”
FIGURE 15-15: Combining ii-V-I chords with modes
The Melodic Minor Scale
When ii-V-I or ii-V-i chord progressions are altered in some fashion, you will need to think about other scale choices. Often, the melodic minor may be used to navigate over certain altered chords. First of all, note that, in jazz, the melodic minor is used while ascending and descending. Let's look at some examples:
ii1 (, C, D, and E (F melodic minor) may be used to build solos or melodies.
Another use is the melodic minor over a V chord that contains either a flat nine or a sharp nine. In both cases, the melodic minor scale located one half step above the root of the chord should be used. For instance, you may use the notes G#, A#, B, C#, D#, E#, and F double sharp (enharmonically a G natural) in conjunction with a G7(9) chord.
Lastly, the melodic minor scale is the perfect choice when using minor-major seventh chords (see Chapter 6). For example, if you see a Gmin(maj7) you would use an F melodic minor scale to solo or build a melody.
The Diminished Scale
One additional scale you should definitely be familiar with is the diminished scale. Also called an octatonic scale, the diminished scale may be used with altered dominant chords when you have a flat nine and a natural thirteen. They may also be used over plain vii° (or vii°7) chords. There are three points to remember when using a diminished scale:
The diminished scale moves in a whole-step-to-half-step manner or a half-step-to-whole-step manner only.
Because of the half-whole or whole-half intervallic model, there are really only three different diminished scales found in the twelve-note western system.
Choosing the correct diminished scale can be confusing. To make sure you implement the right one, try this tip: play a diminished seventh chord located one whole step above the written vii°7 chord (e.g., if the written chord is a F dim7, you would play a G dim7). The combination of the notes found in both chords comprises the correct scale. In other words, if the written chord were F dim7, you would reference it with a G dim7. The combined notes become: F, G, A is spelled as a C# in the scale.)
If the chord is an altered dominant, like G7(9), this method becomes a little more complex but no less effective. Here's how it's done: Take the seventh of the written chord and build a diminished seventh chord using the seventh as the root. In this example, the seventh of a G7 chord is an F. Given this, you would build a diminished chord on F. This becomes Fdim7. From here, follow the instructions as detailed above. In other words, reference this chord (Fdim7) with the diminished seventh chord found a whole step higher (Gdim7). When you do this, the notes for the correct diminished scale are revealed (see Figure 15-16).
FIGURE 15-16: Using a diminished scale
In summary, when working with scales, whether as a soloist or a melody writer, you should avoid excessive “runs” up and down the keyboard or guitar, etc. This tends to sound non-musical and mechanical. Instead, you should use modes, together with arpeggios, chromatics, and other ornaments, to create lyrical phrases. See Chapter 8 for information on chromatics and review Figures 8-8, 15-9, 15-17, and 15-18 for examples of jazz lines that employ chromatic passing tones on weak beats.