How do transposition and modulation relate? Are they the
same? In this newsletter we're going to take a look at
both of them and see what makes them tick.
I'm sure that you have had the experience sometime
in your piano-playing life when someone asks you to play a
song -- but in a different key than in which it is
written. It might be a singer wanting you to lower the
song a step so he/she doesn't screech. It might be a song
leader wanting you to play a song in a more comfortable
keys for a congregation or group. It might be a trumpet
player looking over your shoulder and wanting to play
along with you -- but when he/she plays the same note you
are playing, it sure doesn't sound the same!
So....it's your job, as pianist, to get that song
moved to a different key. That's transposition --
playing or writing a
song in a different key than in which it was originally
written.
Modulation is similar but different
-- modulation means the process of getting from the old
key to the new key. In other words, if I'm playing in
the key of C, and then want to play in the key of Eb, I
have to learn to modulate -- move smoothly from one
key to another without being too abrupt and jarring.
There are basicly 3 ways to transpose:
1. by intervals
2. by scale degrees
3. by solfege -- the moveable "do" system.
But since solfege applies
mostly to singers, we will ignore that possibility and
just take up the first two:
1. Intervals: If the
new key is an interval of a minor 3rd above the old key,
then all notes in the song will also be an interval of a
minor 3rd higher. In other words, if you are transposing
from the key of C to the key of Eb, which is a minor 3rd
higher (or major 6th lower -- whichever way you want to
look at it), then all melody notes will also be a minor
3rd higher:
| "G" in the key of
C would become "Bb" in the key of Eb. "E" in the key
of C would become ":G" in the new key of Eb. "A"
would become "C", "B" would become "D", and so on.
All chords would also move a minor 3rd higher. The
"C chord" would become the "Eb chord", the "F chord"
would become the "Ab chord", and so on. |
2. Scale degrees: Each key you play in has it's own
scale degrees. In the key of C the scale degrees are: C=1,
D=2, E=3, F=4, G=5, A=6, B=7, C=8. In the key of Eb,
however, Eb=1, F=2, G=3, Ab=4, Bb=5, C=6, D=7, Eb=8. So if
I want to transpose Silent Night, for example, from the
key of C to the key of Eb, I need to notice what scale
degrees I am using in the key of C, and then use those
same scale degrees in the key of Eb. For example, Silent
Night starts on the 5th degree of the scale, goes up to
the 6th, back to the 5th, then down to the 3rd. In the key
of C that is: G-A-G-E. But in the key of Eb it is
Bb-C-Bb-G. Why? Because the scale degrees 5-6-5-3 are
constant -- we just need to apply them in each key. What
about chords? Same idea. If the chord progression on
Silent Night is the I chord followed by the V chord,
followed by the I chord, followed by the IV chord, etc. --
then in the key of C that means C-G-C-F-etc., but in the
key of Eb it means Eb-Bb-Eb-Ab-etc.
Modulation means
getting between keys,
so let's say you are playing in the key of C, but you want
to get to the key of Eb smoothly, without jarring the
nerves of the listeners. There are lots of ways to do it,
but the main point is that you have to get to the V7
chord of the new key. So from the key of C to the key
of Eb, that means getting to Bb7. How do we do that
smoothly? We look for chords with common notes. Since the
V of the V of the new key would be Fm7, we have C as a
common note. So we hold the C in the C chord, and move the
rest of the C chord to Fm7, then Bb7, then Eb, and presto
-- we are there! I realize that may be a bit hard to
follow with just printed words to follow, but if you saw
it happen (like on a video) you would understand it
instantly, I think.
Hope this has helped you understand both the
process and the difference between transposing and
modulating. To SEE and HEAR the process, read about the
course by clicking on the banner below:
