The Mixolydian mode uses the same intervals as the major scale with one very important exception. Instead of a leading tone, the seventh scale degree is flatted. For example, a G Mixolydian scale uses the notes G, A, B, C, D, E, F, and G. It does not use an F-sharp. This is shown in FIGURE 5-11.
FIGURE 5-11: G Mixolydian Mode
This scale has great applications in the blues since most blues chords use minor sevenths or, as this book sometimes calls them, dominant sevenths. The chords used in a simple C blues are C major, F major, and G major. However, most of the time, pianists will add flatted sevenths to create a dominant seventh chord. The Mixolydian scale fits beautifully over these kinds of chords since it also uses a flatted seventh. However, once again, you will need to be careful of the fourth scale degree since it creates a suspension. What are your options?
Avoid the fourth scale degree altogether.
Resolve the fourth scale degree down to a major third when you use it.
Use it only as a passing tone in fast scalar runs.
One thing's for sure, never hang or linger on the perfect fourth on a dominant seventh chord. FIGURE 5-12 shows you a suspended fourth resolving down to a major third. For more information on suspensions, including a definition of this term, see Chapter 7.
FIGURE 5-12: Suspended Fourth Resolving to a Major Third
Try playing the Mixolydian mode over I, IV, and V chords in C major as prep for playing the blues. Unlike the fourth scale degree, feel free to hang on flatted sevenths. Since this is a blue note, the flatted seventh will make your blues sound more authentic and even “down-home.” FIGURE 5-13 shows you Mixolydian modes in C, F, and G.
FIGURE 5-13: Mixolydian Modes over I, IV, and V Chords