Transposition and Modulation: How To Transpose To a Different Key & Modulate Between Keys

How do transposition and modulation relate? Are they"D", and so on. All chords would also move a minor 3rd
the same? Let's take a look at both of them and seehigher. The "C chord" would become the "Eb chord",
what makes them tick.the "F chord" would become the "Ab chord", and so
I am sure that you have had the experience sometimeon.
in your piano-playing life when someone asks you to2. Scale degrees: Each key you play in has it's own
play a song -- but in a different key than in which it isscale degrees. In the key of C the scale degrees are:
written. It might be a singer wanting you to lower theC=1, D=2, E=3, F=4, G=5, A=6, B=7, C=8. In the key of
song a step so he/she doesn't screech. It might be aEb, however, Eb=1, F=2, G=3, Ab=4, Bb=5, C=6, D=7,
song leader wanting you to play a song in a moreEb=8. So if I want to transpose Silent Night, for
comfortable keys for a congregation or group. It mightexample, from the key of C to the key of Eb, I need
be a trumpet player looking over your shoulder andto notice what scale degrees I am using in the key of
wanting to play along with you -- but when he/sheC, and then use those same scale degrees in the key
plays the same note you are playing, it sure doesn'tof Eb. For example, Silent Night starts on the 5th
sound the same!degree of the scale, goes up to the 6th, back to the
So....it's your job, as pianist, to get that song moved to a5th, then down to the 3rd. In the key of C that is:
different key. That's transposition -- playing or writing aG-A-G-E. But in the key of Eb it is Bb-C-Bb-G. Why?
song in a different key than in which it was originallyBecause the scale degrees 5-6-5-3 are constant --
written.we just need to apply them in each key. What about
Modulation is similar but different -- modulation meanschords? Same idea. If the chord progression on Silent
the process of getting from the old key to the newNight is the I chord followed by the V chord, followed
key. In other words, if I'm playing in the key of C, andby the I chord, followed by the IV chord, etc. -- then in
then want to play in the key of Eb, I have to learn tothe key of C that means C-G-C-F-etc., but in the key
modulate -- move smoothly from one key to anotherof Eb it means Eb-Bb-Eb-Ab-etc.
without being too abrupt and jarring.Modulation means getting between keys, so let's say
There are basically 3 ways to transpose:you are playing in the key of C, but you want to get to
1. by intervalsthe key of Eb smoothly, without jarring the nerves of
2. by scale degreesthe listeners. There are lots of ways to do it, but the
3. by solfege -- the moveable "do" system.main point is that you have to get to the V7 chord of
But since solfege applies mostly to singers, we willthe new key. So from the key of C to the key of Eb,
ignore that possibility and just take up the first two:that means getting to Bb7. How do we do that
1. Intervals: If the new key is an interval of a minor 3rdsmoothly? We look for chords with common notes.
above the old key, then all notes in the song will alsoSince the V of the V of the new key would be Fm7,
be an interval of a minor 3rd higher. In other words, ifwe have C as a common note. So we hold the C in
you are transposing from the key of C to the key ofthe C chord, and move the rest of the C chord to
Eb, which is a minor 3rd higher (or major 6th lower --Fm7, then Bb7, then Eb, and presto -- we are there!
whichever way you want to look at it), then all melodyHope this has helped you understand both the process
notes will also be a minor 3rd higher:and the difference between transposing and
"G" in the key of C would become "Bb" in the key ofmodulating. Just remember this: Transposition means to
Eb. "E" in the key of C would become ":G" in the newplay a song in a different key, while modulation is the
key of Eb. "A" would become "C", "B" would becomeprocess of getting from key to key.