Linking Major and Minor Keys
Using one idea to put all keys into three simple groups.
Considering the Possibilities
Last week we started getting away from the same old key that we tend to go to and incorporated it with a new key. That new key is a minor third interval above the one we always use. There are a total of twelve key positions on the Circle of Fifths and being able to connect two keys in this way can really expand upon what is possible when writing music. Just think of all the things you could do if you could combine multiple keys.
This isn’t just for Jazz. We can use these concepts in any genre of music. Being able to connect keys gives us many options for borrowing chords, modes, and even scales. Metal music is always borrowing in this way with a common overlap between E Aeolian, E Phrygian, and A Harmonic Minor. Let’s take a quick look at what we did last week with four dominant chords.
A Quick Refresher
In a major or minor key we have two dominant chords that we can use that both lead us to a tonic. Below we have C Major and A Natural Minor. They use the same notes and chords. Notice how the chords G7 and Bm7b5 both lead to either C as a major tonic or Am as a minor tonic.
Instead of thinking about major and minor tonics, let’s look at the flow of each dominant chord to a tonic chord. Below we have C and Cm as a potential tonic chord. Each of the four dominant chords (Bb7, Bm7b5, Dm7b5, and G7) can all lead to C as a major or minor tonic. Essentially, we now have four ways of accessing a new key. The below chart shows the flow from any of these four dominant chords to a tonic, but what about the flow away from a dominant chord?
The next chart shows the same idea, but from the perspective of the dominant chord lead outward to a tonic. The flow of the below chart is the same as the flow in the above chart because of the intervals that lead to a tonic: iiø, V7, bVII7 and viiø all lead to a tonic I or i chord. Take a moment to compare the roman numerals in these two charts to see that they are the same. The difference is the chord we are coming from or going to. Now let’s put this into practice and start changing keys.
Spinning In Circles
We can connect four keys on the Circle of Fifths in a square or diamond pattern. Look at the flow of the four arrows on the circle below.
We can play a little vamp (a movement back and forth between two chords) like Am to and from C. This would use the minor and major tonic chords in the key of C Major / A Minor. After a few bars of this we can play the G7 chord and lead to either C or A. Instead of using G7 to C, we can change the key by going from G7 to Cm. We can use the same format in each of the above four keys to quickly move around the entire circle. Check out the chord progression below and watch how the roman numerals allow chords to have similar functions.
If we drop the root note of any dominant 7 chord, we get a diminished triad: G7 (G-B-D-F) becomes B° (B-D-F). This allows us to substitute a diminished or half-diminished chord for the dominant 7 chord. Below is the same progression, but with half-diminished chords leading up a half-step to a minor tonic.
Going In Reverse
This movement between four keys can continue as long as you like, but what about going backwards? Thankfully we have two more dominant chords that help us do just that.
Using a similar chord progression that starts with the minor and major tonic chords, we can use a bVII7 to turn the minor chord into a major tonic. In each set of four bars we have a I chord with the fourth bar changing the I chord. For example, in the below progression bars one through three use C as the I chord. G7 then tonicizes A as the new I chord. This carries on as the I chord until E7 tonicizes F#. The pattern of the vi chord becoming the new I chord continues until we get back to C as the I chord.
In all the progressions that we’ve used so far, we are (1) playing chords from a key, (2) using a dominant chord to target a new tonic, and (3) using chords from the key related to the new tonic. The next two charts use half-diminished chords to target a new tonic. If you play through both charts, then you’ll see that we are moving around the Circle of Fifths in a clockwise direction. The only change is the dominant chord. Listen to how coming from a iiø or viiø has an effect on the feeling for the major tonic chord. Using different dominant chords helps us change the “flavor” of the targeted tonic chord.
A Three Key System
Using dominant chords to target multiple major and minor chords allows us to switch between keys. This also connects those keys. So far, we’ve used the keys C, Eb, Gb/F#, & A. There are two other sets: G, Bb, Db/C#, & E along with D, F, A, & B / Cb.
With only three sets of keys, we can treat each key as being relative to three other keys. For example, C Major / A Minor can connect to Eb Major, C Minor, A Major, or F# Minor. From any of those keys we can connect to Gb Major / Eb Minor. These connections can go clockwise or counterclockwise, so all four keys can be treated as one system.
Keep using your favorite keys. Just be sure to mix in one that is related to it from time to time. This will keep you on your toes when practicing and will make you a more effective musician.
Keep in mind that if you want to jump across the circle from C Major to Gb Major you can still use a dominant chord to target Gb. The effect of changing keys in this way is two minor third intervals, or a tritone. The tritone itself is responsible for the tension in every dominant chord we have used. Changing keys by a tritone has its own flavor, so try it out if you are feeling bold.
As you practice moving between keys be sure to end with the key that you started on. Changing keys takes your listener on a musical journey. You can travel to all kinds of places, but starting and ending at home will always make sense. Now go enjoy your own journey. Until next time.
