For the guitarist of today, modal harmonization is a very useful skill that makes comping more fun and soloing more interesting. In addition, modes can be used to help visualize how the fingerboard works.
What is a mode? A major scale is made up of seven tones. Seven corresponding modes are formed by starting on each successive note of the scale. We won’t cover them all here, but we’ll explore the three most common ones.
The first mode is the same as the major scale and is called the Ionian mode: C, D, E, F, G, A, B. The Ionian mode is known as a major mode because the distance from the starting note C to E is a major third.
By harmonizing the notes of the modes we can create what are called modal voicings. Using only notes of the C major scale we can create distinct moods or styles. Experiment with these voicings in various combinations. When played over a bass line or simple chord pattern, some will blend well while others have a tense or unresolved quality. These aren’t just chord progressions, but can also be used as riffs for chord soloing and fills.
Let’s start with the Ionian mode and play the voicings in
Ex. 1 against a Cmaj7 groove. Note that each tone in the chord moves to the next available note of the mode and that these voicings are actually inverted triads. The combination of notes in the first voicing determines the feeling and structure of the whole sequence that follows.
The Mixolydian mode is the fifth mode of the major scale (in this case it’s G, A, B, C, D, E, F) and is great for playing over 7th- or 9th-chord situations. The Mixolydian is also a major mode with the major third from G to B. It differs from the Ionian in that it uses a flatted seventh tone, which for this example is F. “All Blues” by Miles Davis is a classic Mixolydian mode tune.
Try Ex. 2 over a G7 vamp.
Example 3 is another hip Mixolydian application in a relaxed 3/4 style over G7.
Many rock and jazz songs use the Dorian mode, which is based on the second degree of the major scale. Tito Puente’s “Oye Como Va” (popularized by Santana) is a famous song based on the Dorian mode. Still using C as our major scale, D Dorian consists of D, E, F, G, A, B, C. This is a minor mode because the interval from D to F is a minor third. Try Ex. 4 for a nice fill between verses or a cool soloing idea over a Dm groove.
Intervals other than thirds can be used to harmonize modally. In the following example the intervals of the major and minor second are used. These have a more complex and pianistic sound. The fingerings are more difficult and involve some longer stretches. Play Ex. 5 slowly against a C or Cadd9 chord vamp.
Modal voicings can allow you to expand your sonic palette with a small amount of effort. The surprising thing is how easy to use they are, and how familiar the voicings feel once we learn to apply them.