Reverse Chord Finder Pro

This is not your regular chord dictionary for the iPhone! Instead, Reverse Chord Finder Pro tells you the names of the chords that match the notes you press on the piano keyboard. This is a great way to find out what chords you're actually playing, and to learn new chords. New in this version: musical score notation!

Fun with the Circle of Fifths, part 3

April 6th, 2008

Ready for more fun with the Circle of Fifths? Here we go!

Minor keys

There is also a circle for minor keys:

I put the names of the minor keys on the inside of the circle. This is because each major key has a relative minor key.

If you don’t have this handy picture around, you can still find the relative minor key. Draw a 90 degree angle from the major key through the center of the circle. The leg will point to the relative minor.

Finding the relative minor, method 1

Or: Rotate the circle so the major key is at 12 o’clock. Its relative minor is now at 3 o’clock.

Finding the relative minor, method 2

Or: Skip two keys in the clockwise direction. Start at Bb, skip F, skip C, then the relative minor is Gm.

You can also remember that the relative minor is the 6th tone from the major scale, or simply go 3 half-steps down. Or go three steps clockwise.

It also works the other way around: each minor key has a relative major key.

Ways to find the relative major scale:

  • Draw a 90 degree angle the other way around.
  • Rotate the circle so the minor key is at 12 o’clock. Its relative minor is now at 9 o’clock.
  • Skip two keys in the counterclockwise direction.

You can also remember that the relative major is 3 half-steps up. Or three steps counterclockwise.

Chords and the circle

Chords that are close together in the circle sound good together in a song.

Every major key has three primary chords: the I (tonic), IV (subdominant) and V7 (dominant) chords. These are easy to find in the circle.

Go to your key, for example C. Go one step clockwise and we find the V7 chord, in this case G7. One step counterclockwise from C is the IV chord, in this case F.

Primary chords in the circle

The V7 chord is the dominant 7th chord. It uses the 1st, 3rd, 5th, and 7th notes from its own major scale, but the 7th tone is flattened.

For example, the tones of the G7 chord are: G - B - D - F. Note that F is not part of the G major scale; it is “borrowed” from the key one step counterclockwise: the key of C.

If you know the V7 chord, then what key are you in? Look counterclockwise one position in the circle. For example, you can tell this way that the C7 chord belongs to the key of F. The tones of C7 are C - E - G - Bb, and that Bb comes from the scale of F.

The following picture shows the 7 “diatonic” chords that can be used in the key of C (without borrowing “accidental tones”). Note that the major chords are neatly grouped together, as are the minor chords.

Diatonic chords in the circle

Chord progressions

Chords like to move counterclockwise in the circle. The G7 chord provides the strongest pull towards the C chord. The D7 chord, in turn, provides the strongest pull towards G.

In songs in the key of C, it is common to see a chord progression such as A7 - D7 - G7 - C.

The chords are not always dominant 7ths, they could also be Am - Dm - G7 - C or Am - D7 - G7 - C. However, they do tend to follow the circle counterclockwise back to the home chord.

You may have heard of the famous ii-V-I chord progression, or 2-5-1. That’s simply a trip counterclockwise around the circle.

In key of C, ii-V-I is Dm - G7 - C. Extended versions of this chord progression exist too, like the vi-ii-V-I or 6-2-5-1 (also called a 1-6-2-5). We already saw that above: Am - Dm - G7 - C.

Chord progressions in the circle

You can go even further and add Em in the mix to get a 3-6-2-5-1. All these chords come straight out of the circle, and the principle works just the same in any of the other major keys.

Tritone substitution

A “tritone” is an interval of three whole tones. There is a concept in jazz music called the “tritone substitution”, or the “flat 5″ substitution. You can use this technique for substituting dominant-7 chords.

For example, you could replace a G7 chord with a Db7 chord. You can do this because G7 and Db7 have 2 tones in common: the B and the F. These two tones just happen to be a tritone (i.e. three whole tones) apart. It may sound a little weird at first, but jazz cats like it.

There are several ways to figure out what the tritone substitution chord is, but you can also look into the circle. The substitution chord is the one directly across. Draw a line from G through the center of the circle and you’ll end up at Db. And that’s your tritone chord.

Finding a tritone substitution using the circle

That’s about it for now. I’m sure there are many more interesting uses of the Circle of Fifths. If you know of any, tell me. :-)

Leave a Reply