A8 | Transposition and the rondo form

Listen to this

What is transposition?

Transposing music means to move from one key to another. This can be useful in many respects:

  1. it creates variety within the unity of the music and a theme can be repeated in a different key without straying too far from the original idea.
  2. a different key can be used to define a different SECTION within a piece of music. This intonation is called a ACTIVE INTONATION. Follow the video link. The concerto movement for French horn, Mozart’s No 4, is structured as a RONDO. This means that the main theme returns time after time. The different sections can be labelled as follows. Can you hear them?

https://www.youtube.com/watch?v=VEJFuWgkGkY

A

B

A

A

B

A

E major TONIC key

B major DOMINANT

A

C minor RELATIVE MINOR key

A

A

  • Section A is the main theme. It is in the tonic key of E major.
  • Sections B and C include several transpositions but section B is mainly in the dominant key of B major, whilst section C is in the relative minor key of C minor.
  • A concerto usually consists of three movements. Here you will hear the final movement, which consists of the RONDO structure which is very popular in such a piece.
  • Despite the key of E major being shown for the whole piece, it is easy to say that section B is in B major as ONE musical note relates to B major – A. This is also the case in section C in C minor, where you are drawn to the C and B notes often in the music.

Recognising a key

The following piece is in the key of D major. So is section A every time. Can you work out the key for sections B and C? Look at the accidentals. As in the case of Mozart’s Rondo, why not begin by looking for the relative keys such as the dominant and relative minor first?

Exercises

A8 - Exercises

Composition task

A8 Composition task