Written and Mental Transposition

Sometimes we need to shift certain notes to a different position or pitch in the sheet music of a piece in order to suit whatever we need at a particular moment. This is a problem that transposition solves. To learn more about this important technique, be sure to read this article.

What is transposing?

Transposing refers to performing or rewriting a piece of music in a key different from the one in which it was originally written. This is done in order to adapt that musical passage to whatever instrument or voice type is needed. For example, if a violin melody must be played by a double bass for some reason, the pitch will have to be changed so that the instrument can play it. The same happens in a choral setting: if a baritone part needs to be sung by a soprano, the melody must be raised to fit her range.

Transposition can be done either in writing or even mentally. Below I'll explain both types:

Written transposition

In this type of transposition, the position of the notes is changed according to the interval by which you need to transpose. To begin, you place the new key signature you'll be transposing to. For example, if we're in C major and we want to go up a whole major second, the new key will be D major.

Once you have the new key, you proceed to change the position of each of the notes. In the example we gave, you'll need to raise everything by a major second. With this in mind, it's important to keep an eye on the new accidentals indicated in the key signature and, of course, on any accidental alterations that may come up along the way.

Mental (sight) transposition

This is done by changing only the clef, so that the notes written on the staff stay in the same place. This way, the only thing that changes is the name of those notes, not the position where they sit.

This technique is much trickier than the previous one. To master it perfectly, you need to be able to read music in every clef, and you also have to be clear about which new key signature you want to reach, as well as any accidental alterations the music may have at a given moment.

It's worth noting that this type of transposition follows some additional rules:

• If the key you're transposing to has more sharps or fewer flats than the original in the key signature, but the music calls for accidentals, those notes must be played or sung a chromatic semitone higher. In this case, a double flat becomes a flat, a flat becomes a natural, a natural becomes a sharp and, of course, a sharp becomes a double sharp.
• Conversely, if the key you're transposing to has fewer sharps or more flats than the original in the key signature, but the music calls for accidentals, those notes must be played or sung a chromatic semitone lower. This way, a double sharp becomes a sharp, a sharp becomes a natural, a natural becomes a flat, and a flat becomes a double flat.

Following these rules is of great importance for ensuring flawless technique.

As you've probably realized, transposition is no simple task. To do it, you need a solid command of intervals, key signatures, and reading in different clefs, which is why constant practice is recommended. You'll find that once you've mastered it, you'll use it more often than you'd imagine.