Transposition is a very essential aspect of music every piano/keyboard player should understand.
Transposition is the transfer of same music idea (Chords, Scales etc) from one key to another.
You may recollect that we learned the song “How Great is Our God” in the key of C; however, sometimes you may want to learn the exact song in different keys; that’s where the art of transposition comes in.
How do I Transpose in music?
To effectively transpose music ideas from one key to another, you have to employ the use of the NUMBER SYSTEM.
We talked in-depth about the number system in the beginners’ lesson; hence, you can revisit the lesson by clicking here to go to the music number system lesson
However, in summary, the music number system basically means representing each note or chord of a particular major scale using numbers based on their position in the respective scale.
In Key C major:
C D E F G A B C
1 2 3 4 5 6 7
In Key F major:
F G A Bb C D E F
1 2 3 4 5 6 7
If I played the I – 4 – 1 – 5 chord progression
In key C Major:
C Major Chord – F Major Chord – C Major Chord – G Major Chord
In key F Major:
F Major Chord – Bb Major Chord – F Major Chord – C Major Chord
What we did right there is transposing the 1-4-1-5 idea from Key C Major to Key F Major using the NUMBER SYSTEM.
And it doesn’t end here; you can further transpose to any key using the same method.
Let transpose it to the key of G Major
G Major scale is :
Thus, 1-4-1-5 chord progression is
G Major Chord – C Major Chord – G Major Chord – D Major Chord
Now let’s see if you can transpose this same 1-4-1-5 chord progression to the key of Ab (A flat Major).
Before we go, here is a cheat sheet called the “Transposing Chart.” It contains all 12 keys and the number system for each key.
Simply pick a key from each horizontal row on the left side and interpret any chord progression using the numbers (above) as represented in the chart.
I hope this lesson was insightful?