This is part 2 in a series of video blog posts responding to a common question that I get from my private students. The question is: What can I do to make a "cooler" chord progression? The question has a lot of different answers. Last week, I demonstrated the use of a half-diminished vii (seven) chord in a chord substitution. This week I'm demonstrating how you can bridge 2 adjacent chords with a fully diminished chord. Scroll down to check out the video explanation!
What is a ♭vi° chord?
Chords are often named using roman numerals. We use upper case roman numerals to indicate major chords and we use lower case roman numerals to indicate minor chords. We use lowercase for both half-diminished and fully diminished chords because the quality of the 3rd in these types of chords is minor. The ♭(flat) symbol represents that this chord is not built of the ACTUAL 6th degree, but rather the flat 6th degree. So, we get a ♭vi (in other words, it is based on the flat 6th degree and it has a minor-quality 3rd).
A diminished triad contains the root, minor 3rd and a diminished 5th (same as a #5, pitch-wise). The triad can be called diminished as long as it contains these 3 intervals. Half-diminished 7 chords are diminished triads with a minor 7th. Fully diminished 7 chords (like the one in the video below) are diminished triads with a "diminished" 7th (a.k.a. double-flat 7... the same pitch as a major 6th)...
One of the coolest uses of fully diminished chords is to transition from one chord to another. In the video below you'll see an example of how we can transition from an A to a Bm chord by using a ♭vi° chord.
There are only 3 diminished chords in the world!
Crazy, but true. You see a fully diminished 7 chord contains 3 stacked intervals of a minor third. In this weeks example we are using the notes Bb, Db, Fb and G. From Bb > Db is an interval of a minor 3rd. Db > Fb is an interval of a minor 3rd... and so on. This means that any one of the notes in this chord can be considered the "root". Totally crazy, but true! This chord could be called a Db, Fb or G fully-diminished chord too. All names for this chord are completely valid. Since there are only 12 notes in Western music (a.k.a. the chromatic scale) AND since this chord contains 4 notes, there can only be 3 different fully diminished chord "spellings". Chew on that for a while 🙂
Check out Part 1 of this series about Reharmonizing with Half-Diminished vii Chords
Also, check out Part 3 of this series about Reharmonizing with Minor iv Chords