How to Transpose your music into another Key

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How to Transpose your music into another Key

Postby PeterA » 18 Oct 2017 14:22

Each song is generally based upon a scale. Most popular songs that you play are written in 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 gives 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.

I don’t want to delve here into how each of these chords is built up, but a major scale has this structure, which can be represented by roman numerals:

    I ii iii IV V vi viio ( viio means vii dim ) i.e. a diminished chord
The uppercase Roman numerals represent major chords. The lowercase Roman numerals represent minor chords. The lowercase Roman numeral, usually with a superscript circle represents a diminished chord.

So with a C major scale and using the above Roman numerals, you will have the following chords:

    C Dm Em F G Am Bdim
You can do this with any key.
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. Take the key of C major and suppose 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 = I
    Em = ii
    F#m = iii
    G = IV
    A = V
    Bm = vi
    C#m = viio

So with a D major scale and using the above Roman numerals, you will have the following chords:

    D Em F#m G A Bm C#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.

As you become more familiar with the chords in each key, the more transposing will become second nature. You can use the Circle of fifths to do this, but, I have put together a chart that will help you transpose into any key using the method shown above. To view or print out this chart, click on this link, which will open it up as a pdf document. Do a right-click to open it up in a New Tab.

Key Change Chart

To print it out, hover with the mouse near the top of the page and a PRINT option will appear in the top right hand corner.

Referring to this chart, first look for the key of the song. It's literally the key to how the whole song will go. If you don't know what key it is in, look at the number of
sharps ( # ) or flats ( b ). Then go down the left hand side of this chart until you find your key. Now look across the row. Listed is the basic chord progression for the key, in that some or all of those chords will be found in the song written in that key.

Another clue to the key of a song is what chord begins the song and what chord ends the song. Often, the note upon which the scale is built, called the tonic, will also be the first and/or last note of the song. You might only have lyrics and the chords to a song, but no more information about the specific notes used in the song. If the song begins and ends with the C chord, then that's a good place to start determining that the key your song is in, is C. Most songs end on the key chord, but there are rare exceptions. Many start on the key chord, but not as many as those that end on the key chord.

Once you've found your key, you'll want to decide what key you will be changing to. If the song you have is written in the key of C, for instance, and you want to try out how it will sound in the key of G, just take the chord C and replace it with the G. Take all the Dm chords and replace them with Am, and so on until you've changed all the chords.

There may be some variations of chords, but this basic template remains the same. If you find that there is, for example, a G7 chord in your song, then when you transpose it into the key of G, replace the G7 chord with the D7 chord. As long as you go column by column as you change the chords you will be correct.

For most of us, we will most likely want to transpose from a key with many sharps or flats, to one with less.

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Re: How to Transpose your music into another Key

Postby papadeedee » 18 Oct 2017 17:50

Hi Peter,
A very good opening contribution, very informative. :D :D
I can only think of two occasions when a tune doesn't end with the key chord.
1, Tierce-de-picardie, when the last chord played is a major chord when the tune is in a minor key.
2, Tango usually finishes with a Dom 7 chord.
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Re: How to Transpose your music into another Key

Postby Brian007 » 18 Oct 2017 18:55

Hi Peter,

An excellent source of reference which I am sure I will need to keep referring back to in the future.

Brian007 :D :D
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Re: How to Transpose your music into another Key

Postby papadeedee » 19 Oct 2017 13:28

A little more on your excellent post Peter. Of course you are perfectly correct when you state that Upper case = Major, and lower case =minor.
FOR CONVENIENCE, I normally just type the numbers in upper case. I will try to clarify my reasons. In many tunes, not all chords are diatonic.
If the chord is Major, I normally leave just the number or I may add (M), if it is minor, I add a small (m) and if it is dominant, I add a (7).
eg, to transpose from C major to F major, to begin I normally write out the following.
1 11 111 1V V V1 V11
C - D - E - F - G - A - B
F - G - A - Bb - C - D - E

The lady is a Tramp. The first four bars.
1M 7 - 1 m7 - 11 m7 - V 7
CM7 - Cm7 - Dm7 - G7
FM7 - Fm7 - Gm7 - C7

The turnaround in C major is C -A7- D7 - G7 all Upper case, 1-6-2-5.
instead of continually changing from upper to lower case I find it easier to use the recognised symbols to indicate the quality of the chord.

Diatonic four note chords in C major are : CM7, Dm7, Em7, FM7, G7, Am7, Bm7b5 (B half diminished)
The major scale formula is TTS TTTS (T=tone and S = semitone)
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