Tonal Transposition

Transposition means playing a tune in another key
Transposition arises mainly in two situations

  • Put the music in a more suitable range: Especially for vocalist .Or for an easier fingering as seen in Schubert’ unfinished symphonyinachWith the Bb  clarinet this example is very difficult to play and the phrasé and intonation are  foolhardy. In some case, it allows to to extend the range of a timbre. The A clarinet can reach the C# (in pitch tone) insted of D with the Bb clarinet.
  • Write for transposing instruments ie that sound differently from written note

In the case of transposing instrument the aim is to keep the same fingering so that one can interchange instrument

For example alto sax Eb and tenor sax Bb would play C D E with the same fingering but it sounds Eb F G for alto sax and Bb C D for tenor sax

Technique (Especially for transposition at sight)

    1. Determine the interval of transposition

The interval is measured from the key of the transposing instrument to C (no sharp, no flat)

    1. Change notes name with help of clef

To determine the transposing clef

      • write the transposing note in treble clef (Bb for a clarinet in Bb for example)
      • Call this note C
      • Search the corresponding clef which is C,F or G
      • Use de correct key signature

The new tonality is given by C written in treble clef ,read in the new clef

    1. Adapt accidentals

This is the real difficulty that occurs frequently in minor mode.

Flats and sharps are not taken into consideration to find the clef

Practical method

From the previous page it brings out that there are only three reversible steps in transposition that will add or substract flat or sharp to initial tonalities

Direction is given by clef

Here is a practical table that indicates the reading clef and change in key signature

To change  transposed part into real sound take the alternative with same step

example: to play piano part with clarinet in Bb :Use alto clef and add 2 #

To play Clarinet Bb part with Piano :Use Tenor clef and add 2 flats

Transposing instruments
More about clef

More about Key signature