How to Transpose or Change the Key of a Chord Chart

What do you do if you find a chord chart of your favorite song, but it’s not in the right key?

The term transpose simply refers to changing the key of a song. You can transpose a piece to either a lower pitch or a higher pitch. So for example, you find a chord chart is in the key of A but you want to play it in the key of G. Surprisingly, this isn’t very difficult to do if you know a small bit of the theory behind it.

Let’s look at this.

Scales and Roman Numerals

Each song is generally based upon a scale. Most popular songs that you play on the guitar are based on the major scale. There are seven notes in a scale. So in the key of C major, you have the notes: C D E F G A B.

The chords of that song are then built off of each note of the scale, which would give you seven chords for that key. However, each of these chords will have a different sound. Based upon a major scale, some chords will be major, others minor, and one chord will be diminished.

We don’t have time to look into how each of these chords are built, but a major scale has this structure, which can be represented by roman numerals:

I   ii   iii   IV   V   vi   vii^o

The uppercase roman numerals represent major chords. The lowercase roman numerals represent minor chords. The lowercase roman numeral with the superscript circle represents a diminished chord.

So let’s take a C major scale and use the above roman numerals. In a C major scale, you will have the following chords:

C   Dm   Em   F   G   Am   Bdim

You can do this with any key.

So what’s this have to do with transposing?

When we identify the chords of a key by roman numerals, it makes it easier to transpose to another key. Here’s how this works. Again, let’s say we are in C major, and we have a chord progression like this:

C  F  Am  G

Let’s transpose this up to D major. First, we must identify each chord with a roman numeral.

C   F   Am   G
I   IV  vi   V

We want to take the progression that is in the key of C major (C – F – Am – G) and move that up to D major. Since we know the progression is I – IV – vi – V progression, all we have to do is figure out what that progression is in D major.

So let’s identify each chord in the key of D major with a roman numeral.

D  Em  F#m  G   A  Bm  C#dim
I  ii  iii  IV  V  vi  vii^o

As we can see, the “I” chord is “D”, the “IV” chord is “G”, the “vi” chord is “Bm”, and the “V” chord is “A.” So our transposed chord progression in the key of D major is D – G – Bm – A.

Key Change Chart

As you become more familiar with the chords in each key, the more transposing will become second nature. However, I’ve put together a chart that will help you transpose into any key using the method shown above.

Key     |  I   ii   iii   IV   V   vi   vii^o
C major |  C   Dm   Em    F    G   Am   Bdim
D major |  D   Em   F#m   G    A   Bm   C#dim
E major |  E   F#m  G#m   A    B   C#m  D#dim
F major |  F   Gm   Am    Bb   C   Dm   Edim
G major |  G   Am   Bm    C    D   Em   F#dim
A major |  A   Bm   C#m   D    E   F#m  G#dim
B major |  B   C#m  D#m   E    F#  G#m  A#dim

Do you have any tips or shortcuts for transposing a key?

About Brett McQueen

Brett McQueen is a musician, songwriter, and the founder and editor of Guitar Friendly and Ukulele Tricks. Learn more about him here and follow him on Twitter at @GuitarFriendly.