Transposition or transposing in music means playing or writing music in a way that makes it sound higher or lower. This can be done by playing or writing the music in a different key, or by playing or writing it up or down an octave, without changing the key.
Transposing is a useful skill for people who play an instrument, especially the piano, organ, or some other keyboard instrument. If a pianist is accompanying a singer and the song is a little too high for the singer’s voice, it is very useful if he is able to transpose it down so that the music sounds in a lower key. For example, if the music is written in the key of C major, it could be transposed down a whole tone so that it sounds in B-flat major.
Most electronic keyboards and organs these days have buttons which can set notes to transpose automatically. This can be very useful, although it may be confusing for people with absolute pitch.
How to transpose
It is a good idea for people who play keyboard instruments or other kinds of transposing instruments to practise transposing. There are two ways to do this:
- Transpose each note, one at a time. For example, when transposing from C to B-flat major, each note has to be one tone lower: an A becomes a G, a G becomes an F, an F becomes an E-flat, and so on.
- By watching or hearing the intervals between the notes in of the music and thinking of the same thing in the new key. For example: when a note leaps up a major third in the old key, the same needs to happen in the new key.
Transposing by intervals is the a better way of transposing, but when people transpose they sometimes also transpose the notes the first way, one by one.
There is another possibility which sometimes works: by thinking in a different clef. For example, someone who is used to reading music in the alto clef, such as a violist, can transpose up a tone from music written in the treble clef by imagining it was written in the alto clef and playing an octave lower (a note on the middle line in the treble clef is a B, but in the alto clef it is a C). They could also imagine the new key signature of 2 sharps – it becomes a C sharp.