The fifth degree of the blues scale, also known as the dominant, carries the responsibility to help create, sustain and climax musical tension. Interesting in that even when all of the blues chords use the dominant seventh color, as say in a 12 bar 1, 4, 5 blues, motion to the Five chord still creates the musical tension which is released upon the striking of the tonic or One chord. Melodically, the fifth degree acts a kind of a herald, when we here this pitch our attention is oftentimes cued into thinking that some event is going to happen. We begin to anticipate an arrival of something musically cool. In other art worlds of theatre, opera, t.v. scores etc., where dramatic action among people is portrayed in the music, it is the fifth degree that helps to set up, create and sustain the excitement and tension so effective in presenting new twists, surprises and the building of emotional drama in the storyline.
Needless to say, the fifth degree is a very powerful player in our musical world. Perhaps even more so than the tonic, where the musical tension comes to rest. The fifth is the mover, the pitch that, once the tonality has been established, is usually the last stop in the building of musical tension before it's release. Whether the resolution and release of tension is to the tonic ( One ), flat Two, Four, relative minor or wherever the composer decides it should go, the fifth or dominant scale degree focuses the musical energy and tonal direction. It's kinda like the traffic cop of harmonic motions. With this in mind, this first musical idea simply sets up motion to the tonic by striking the fifth in a bluesy color and format, the lick reminiscent of Duke Ellington's C jam blues. Example 1.
Same idea as above rewritten in the minor tonality, up tempo minor blues idea. Example 2.
New idea, minor tonality. Off beat rhythm strengthens the ascending nature of the line anchored by the fifth degree. Example 3.
Similar idea, major tonality. The alternating thirds is a common bluesy motif. Example 4.
Similar idea, minor tonality. Here the line reverses directions. The first three notes in bar 17 are a very common blues combination of pitches. Example 5.
Similar idea, major tonality. Basically a descending, permutated blues scale. Cool bass line huh? Example 6.
Check out the fifth scale degree in other musical capacities.
| major scale | diatonic chords | Mixolydian mode |