The first step in familiarising yourself with transposition is to memorise the pitch names of the various transposing instruments. For the conductor it is essential that these become second nature, including the correct octave in which the instrument plays. If the octave is incorrect, then the transposition is incorrect. For instance, even though all stringed instruments sound at concert pitch, string bass sounds one octave lower than written. This is the same for contrabassoon, while piccolo sounds an octave higher. These octave differences must be recognised and analysed correctly.
Regarding brass instruments, the trumpets normally used in today’s wind orchestras are in B-flat while in the orchestra, the trumpet is often pitched in C, which makes it a non-transposing instrument. Occasionally trumpets in D, E-flat, or F are required. All of these sound higher than written. Trombones, euphoniums, and tubas of various pitches, all sound as written except in some wind band traditions and in the brass band tradition where all instruments, except the bass trombone, are notated in treble clef. Sometimes, particularly in older scores, French horn parts may be notated in the bass clef, in which case they normally transpose using the inversion of the interval of the treble clef.
If you have never played a transposing instrument, one of the best ways of understanding the issues involved is to play passages, transposing them at sight. A list of common transposing instruments can be downloaded (listed in tab “Download transpositions”). The only instrument missing from the table is the Alto flute in G which sounds down a perfect fourth. In the past, composers used many transposing trumpets and horns in order to suit the tonality of the piece. A more complete table of these transpositions can be downloaded from the next tab.
(Spend around an hour on this activity and revisit it if you need to develop your skills)
Here is a theme written at concert pitch. Transpose it for every instrument on the table, either by playing at sight, or if you get stuck, but writing it out, remembering to add the correct key signature. If you are new to transposing, you may want to only attempt the first few notes. If you have more experience, try to do the whole phrase. To make it even more challenging, try to mentally hear it in each transposition and then test yourself against a piano.
It is helpful to understand the tonal structure of the melody to be transposed.
- Check for outlined chords
- Check for scale patterns
- The start of this passage uses chords I-vii (or V7 without its root note) resolving to a B flat major ascending to the 6th degree. This can easily be thought out in any key.
To help you get started, here it is as you will find it in the score, written for clarinet in B flat.