Transposing a piece of music means (it can be chord
progression or melody) playing it in any key that is different to the one in
which it is written or the one in which you originally learned it. There are
two reasons why you might want to transpose a chord sequence. First you may
want to sing along with it but find that it is too low or too high for your
voice. Second, you may want to use chord shapes or add melody notes which are
difficult to play if the music remains in its original key. Transposing the
chord progression to an appropriate new key can help to solve both these
problems.
Before we learn to start transpose a song let’s first learn
the Roman numeral system by which you can identify each chord in a key by a
Roman numeral. The 1st chord is (I) the 2nd chord is (II) third chord is (III)
fourth chord is (IV) fifth chord is (V) sixth chord is (VI) and the seventh
chord is (VII). You can give the chord its position name by above given numbers
or you can use simply 1,2,3,4 whatever you like. Each chord also has a name
according to its position in the scale and its Roman numeral as given below:-