This tutorial was written in response to an e-mail enquiry I received from Jean Jones.
Sometimes you will have a piece of music wriiten in one key which you want to play in a different key. This may be for any of a number of reasons. Not all instruments are chromatic - the piano, the guitar, etc. give you the benefit of having all the possible notes available to you. Other instruments only have a limited range of notes and are tied to a particular key. Also, the original key of the piece may not be within a suitable tonal range - for example the vocal line could be written in a higher key than you can comfortably sing.
Once you're comfortable with the basics of scale theory, the process of transposing (i.e. changing a piece of music from one key to another) isn't really as difficult as you might expect. Before proceeding with this tutorial, it is worth familiarising yourself with the material covered in the tutorials Meet the Major Scale and Numbering Scalar Tones, as well as the Building 7th Chords. These cover subject matter which is very relevant to what we'll be looking at here.
As an example, let's suppose that we have a piece of music written in the key of A major which we'd like to transpose to the key of F# major. Have a look at the following couple of bars.
You can tell that this is in the key of A major, by looking at the key signature (as if it wasn't enough of a clue for me to tell you, just a couple of sentences ago, what the key was).
As a starting point, we need to identify which degree of the key each note is (e.g. in the key of A major, A=1, B=2, etc.). For this example piece, this gives us....
Now we need to know what notes occur on these degrees in the 'target' key...
| A major | A | B | C# | D | E | F# | G# |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
| F# major | F# | G# | A# | B | C# | D# | E# |
Having done that, we can write the piece out again, but using the corresponding notes from the key of F# major (and don't forget to change the key signature!):
Chords are just collections of notes, so you could approach transposing a chord progression in the same way as transposing a melody; that is, taking each note, numbering it and moving it to the 'target' key. However, there is a useful shortcut which you can use.
Let's use this simple chord progression in the key of C major, and transpose it to the key of D major:
Instead of numbering each note in turn and moving it to the new key (potentially a long and laborious process) we can consider how each chord relates to the parent key:
Now, we can think about the chords which belong to the 'target' key.
| C major | C 7 |
Dm7 | Em7 | F7 |
G7 | Am7 | Bø7 |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
| D Major | D7 |
Em7 | F#m7 | G7 |
A7 | Bm7 | C#ø7 |
We can now rewrite the piece using the new chords. Again, don't forget to change the key signature:
That was a fairly brief introduction to the theory behind transposition. I always try to keep these tutorials as succinct and to-the-point as possible, and sometimes it feels like there's an awful lot crammed into not a whole lot of words. This is one of those times.
Take some time to read and understand the material covered here, and then try transposing a few pieces of music for yourself. Putting the theory into practise is often the best way of reinforcing your understanding of what's involved. With this, as with anything else on this website, you're welcome to contact me if you'd like me to explain anything in more detail.
How useful did you find this tutorial?