My experience teaching guitar has led me to believe that the biggest problem most jazz students have is their inability to clearly define the sound of a chord when playing single-note lines. Even with all the material available these days, most students feel overwhelmed by so many chords and so many scales. Fortunately most of the chords we encounter in the jazz idiom can be reduced to one of four types (major 7, dominant 7, minor 7 or minor 7b5), and because of this, we can use one scale to capture the sound of all of them. This lesson discusses the makeup of these common chords and how each one can be clearly defined by familiarizing yourself with one seven note scale.
Every chord is comprised of set of intervals above the root (for example a major 7 has notes a major 3rd, perfect 5th, and a major 7th above the root), and each chord uses certain extended notes to add color to the basic chord (ex. a major 7 chord uses a 9th, #11, and a major 13 for color). Below is a breakdown of the chord tones and extensions (in brackets) for each chord type.
Major 7 = Root 3 5 7 [9 #11 13]
Dominant 7= Root 3 5 b7 [9 11 13]
Minor 7= Root b3 5 b7 [9 11 13]
Minor 7b5= Root b3 b5 b7 [b9 11 b13]
If you're a guitarist, you probably know at least one fingering of the minor pentatonic scale. Add two notes to it and you get a seven note scale that can be used over any major 7, dominant 7, minor 7, or minor 7b5. For example, G minor pentatonic includes the notes: G, Bb, C, D, and F. If we add A and E to it we get: G-A-Bb-C-D-E-F. By the way, this new scale could be called the G Dorian mode, but I'll save the discussion about modes for a later lesson. Our next step is to practice playing this scale over the entire neck of the guitar. Again, this shouldn't be totally new territory because we're building on something we already know: the minor pentatonic fingerings. Practice example 1 until you can play this scale in each of the four positions from memory. As I mentioned before, most beginner/intermediate players have problems playing over chord changes because they did not complete this task, or they just plain skipped it altogether.
Now we will apply our scale: G-A-Bb-C-D-E-F to the four chord forms mentioned above. (note: by applying our scale to the chord tones AND extensions of each of these four chord types, we can be sure our scale will generate the full range of sound for that chord type). Below is a list of the four chords that share our scale. Notice how the notes of our scale fit perfectly with the chord tones AND extensions of each chord form.
Bb major 7
Root 3 5 7 9 #11 13
Bb D F A C E G
C7
Root 3 5 b7 9 11 13
C E G Bb D F A
G minor 7
Root b3 5 b7 9 11 13
G Bb D F A C E
E minor 7b5
Root b3 b5 b7 b9 11 b13
E G Bb D F A C
It's important that you hear how this scale fits perfectly over each one of these chords, so I recommend that you record each chord separately and practice playing melodies from our scale over each one of them. Play the same ideas over different chords and hear how these notes take on a different identity when the chord changes, all the while sounding tonic to the harmony. Play each chord for at least three minutes so you will have enough time to improvise several melodies with each chord as the harmonic backdrop.
Applying this method in the future means that you see how the scale fits over each chord type. Whenever you have a major 7 chord, play the scale down a minor third from the root of the chord. Dominant 7 chords use the scale up a 5th. Minor 7 chords use the scale that begins on the same root, and minor 7b5 chords use the scale that begins a minor third up from the root of the chord.
G-A-Bb-C-D-E-F = G minor7, Bb major7, C7, E minor7b5
It takes time, but eventually you will arrive at the point where you are presented with a chord and will know immediately how to play the sound of that chord in your solo lines. Be patient and good luck.