Transposition in Q4 and Q5
In the grade 6 ABRSM Music Theory exam you will definitely be asked to transpose a few bars of music from an orchestral score. Most often it is a horn transposition, but you may additionally be asked to transpose for trumpet, clarinet or cor Anglais.
To transpose music into another key, you need to first know the interval and direction of transposition. (You will need a good understanding of key signatures and intervals in order to be able to transpose confidently.)
If you are doing the task for a transposing instrument, you need to know whether you are moving into or out of concert pitch. Players read their music at written pitch, but it’s sometimes useful to see the music as it will actually sound, at concert pitch.
Most instruments transpose down into concert pitch and up into written.
The name of the instrument often includes its transposition pitch (e.g. clarinet “in Bb”), but there are quite few exceptions, including all those that transpose at the octave (e.g. the double bass). The transposition interval can be worked out from the instrument’s name in relation to the note C. For example, Bb is a major 2nd lower than C, so we would transpose down a major 2nd into concert pitch for a Bb clarinet. The horn “in F” sounds a perfect 5th lower, because F is a perfect 5th lower than C.
Start by transposing the key signature. NB: you don’t need to work out whether the music is major or minor. Just assume the key signature is major. Here is a melody to transpose:
Using the keynote (tonic) of the major key represented, work out the new keynote by transposing at the required interval. (For example, starting on a keynote G and moving down by a major 2nd, the new keynote is F. Moving up a perfect 5th from G, the new keynote is D. Moving up by a minor 3rd from G, the new keynote is Bb.)
Then add the key signature which matches your new keynote. Here are some transpositions of the original keynote:
Then transpose each note in the melody in turn. There are many ways to do this quickly; the best method often depends on how distant the transposition is.
When transposing by a 2nd, the easiest way is to simply move the note up or down from a line to space (or vice versa):
When transposing by a 3rd, move the note to the next line or space:
For larger intervals, it may be easiest to count up or down the stave using the point of your pencil to keep your place.
When you meet a note with an accidental, think about how the accidental alters the original note, and in which direction. For example, the C# in bar 2 raises the note C by a semitone. In your transposition, choose the correct accidental which will have the same effect. When we transpose this melody into F major, we will need the note which is one semitone higher than Bb, which will be B natural (not B#!) The accidentals in your transposition will appear in the same places, but the type of accidental needed might change. Try to use the correct enharmonic equivalent – for example the last note is Db and not C#, because Db is a major 2nd lower than Eb, whereas C# is a diminished 3rd lower.
You will probably also need to change the stem direction on some of the notes – check carefully.
Here are the other transpositions: