jbauschatz
commented
9 years ago Note that the root of the progression is essentially the key we're playing in, but that doesn't determine how we name notes within the progression - that's kind of built into the chords in the progression already. A chord built on the fifth degree of the scale will have a flatted seventh, IF we are only working with notes in the original scale. These are called diatonic chords. But a chord progression is free to violate the diatonic chords resulting in notes outside of the root note's scale.
Add methods and services for constructing chord progressions.
A chord progression is abstractly a sequence of scale degrees coupled with chord types - for example {I major, IV major-seventh, V seventh, I major}
A chord progression becomes concrete when built off of a root note, and all the chords based on degrees of the major scale. For example building the above off of C gives us {C major, F major-seventh, G seventh, C major}