#6
If your chord progressions sound a little stale, why not use diminished seventh chords to beef things up a bit? Diminished seventh (or ‘dim7’ from here on out) chords are nowhere near as scary as they sound - once you know the formula for how to put them together, they’re pretty easy to suss.
This is down to the unique, symmetrical way in which a dim7 is structured, with all four notes in the chord separated by the same pitch distance or interval - three semitones. This in turn means that, by shifting each of the three chord shapes up or down three semitones, you can cover four different chords with the same shape, each chord rooted on whichever note is at the bottom of the stack you’re currently playing. This way you can use the same three shapes to cover all 12 chords in the set.