Harmonic sequence

When you encounter a chord progression that acts as an exception to the harmonic function flowchart it may be because it's actually a sequence but for the chords.

Example

I    ∣    V    ∣    IIm    ∣    VIm    I \;\; | \;\; V \;\; | \;\; IIm \;\; | \;\; VIm \;\;
  • I -> V is normal
    • Movement: a 5th up
  • V -> IIm is "weird"
    • Movement: a 5th up
  • IIm -> VIm is "weird"
    • Movement: a 5th up

So then ii -> vi is I -> V sequenced up a 2nd!

For examples from real songs, see Exceptions Created by Sequences.1