Progressions In Harmony
There is so much to think about when discussing chord progressions it boggles the mind.
A good starting point in understanding chord progressions is the flow inherent in most any musical piece. Fast or slow, happy or sad, poignant or ludicrous, rebellious or patriotic each tune is built around defining the flow of the piece reflected in style, tempo, rhythmic and harmonic structure.
There are two basic overall rhythmic flow types in music: vertical and horizontal. A good example of vertical music would be a John Philips Sousa march where the rhythm is defined by micro stops in time enforced by emphasis. A good example of horizontal music would be a Bill Evans ballad that magically floats thru time and space. Most tunes are somewhere in between.
Musical compositions are based on establishing a tonal center, going away from it, coming back to it. How you do this is dictated by the style of music and the level of the composer/arranger. There are 3 basic types of harmonic chordal progression: diatonic scale motion (Cmaj7, Dm7, Em7, Fmaj7,etc.), cycle of fifthing (C7,F7, Bb7, Eb7, etc.) and going from relative major to relative minor (Cmaj7 – Am7). You must remember that these progression types have been noted in a simplified manner. The amount of sophistication, creativity and inventiveness that can be applied is endless. The goal of jazz progressions is to proceed fluidly forward with no effort.