Modulation: Traveling Smoothly from Key to Key

by Gail Smith

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Maybe you have never had to modulate... but just in case the need arises, I want to discuss the subject.

Several years ago I was attending a funeral service and the organist played one hymn after another in random key order. The stopping and starting in a foreign key was very annoying to listen to. The hymns could have been arranged in an order going from compatible keys that wouldn't have even needed a modulation. This organist evidently was not aware of key relationships. It was the most irritating musical prelude I have ever heard and it nearly drove me crazy! The problem could have been solved by modulating from one song to the next or changing the order of the hymns altogether.

When you play a song in the key of C you can go immediately to a song in the key of F. Then you can go to the key of B flat. Next, the key of E flat; then A flat; next D flat; then G flat. This is the natural key modulation process. This natural order of flats is a perfect way to modulate from one key to another. It is logical and sounds pleasant to the ear. Modulation becomes a problem, though, if you need to move to another key out of order.

Modulation occurs when we change keys within a song or when moving between songs. The traditional way to modulate is by using the dominant 7th chord of the new key. Sometimes the progression is so subtle that it isn't apparent to the listening ear that the tonality is shifting. Finding the right path that leads smoothly to a new key can be frustrating or actually fun. It can be made into a game imagining that you are trying to find your way out of a maze.

Thinking of musical keys as states and then traveling from state to state may make modulation clearer to pianists. Sometimes going from one key to another takes a little more time. We must find the distance from one key to another just as we need to know the distance when we travel from Florida to Alabama. We don't want to go out of the way and ramble along on the wrong roads.

Another way of thinking about modulation is finding the common chords in both keys. For illustration purposes let's think about going from Florida (the key of F) to Alabama (the key of A). What (if any) chords do each key share? They have zero common chords. Well, the only thing we have is common note tones which are: D, A and E. Play those three notes in any order and then go to the dominant seventh chord (E7) in the key of A. This is a simple way to modulate. Try this formula on a mixture of keys for practice. It always sounds good.

Find several piano solos in different keys. Place them from lowest to highest keys. Imagine having to go from the key of B flat to F minor in two measures. One solution is to go to the ii chord of the new key from the old key. An example would be using G minor after the B fiat chord and then using a C suspension chord into F minor. That formula for modulating is II - V - I.

Usually modulations take the melody higher. It is interesting to see examples of modulations in classical music. Sonatas usually went to the sub-dominant key or dominant key. Study the Beethoven Sonatas and look for the key changes.

It is easy to modulate when you are going from one flat to two flats. It is a natural modulation that doesn't require any further modulation. You are able to begin playing immediately in the next key. The order of these keys is: C - F - B - E - A - D - G. We can also modulate in sharp keys from 5 sharps to 4 sharps, etc. The key names are: B - E - A - D - G - C. This is the natural modulation of sharps using the cycle of fourths.

Music naturally progresses in fourths. A G7 chord resolves to a C chord, a C7 chord resolves to F, etc. Study this cycle.

Modulating a half step higher is easy. See the examples below using the V chord of the new key and presto, you are there.

Another quick way to modulate is to go to the IV chord of the new key with the bass note root of the V chord (Four over Five).

Practice the chords in all keys for maximum proficiency. Soon you will be able to modulate to any key.

For more on modulations, see Gail Smith's Complete Book of Modulations for the Pianist.