Most clarinets and trumpets are pitched “in Bb”, which means that the sounds produced by the instrument are a major 2nd lower than written.

written v. sounding

To work out how music written for clarinet or trumpet will sound at concert pitch, we need to transpose the music down by a major 2nd.

The interval of a major 2nd is the same as a tone or two semitones, but not all tones are a major 2nd. The letter name of the transposed note needs to be the previous letter in the alphabet. It is important to use the correct enharmonic equivalent. For example, Gb and F# are enharmonic equivalents, but only F# is a major 2nd lower than G#. G# and Ab are enharmonic equivalents, but only Ab is a major 2nd lower than Bb.

enharmonics

If the original note is in a space, the transposed note will be on a line, and vice versa.

Usually, we also need to transpose the key signature. This is done in the same way. Use the key signature of the keynote which is a major 2nd lower.

transposing key signatures

To transpose from concert pitch back into written pitch, we move everything up by a major 2nd.

transposing from D major to E major

Clarinets can also be pitched in A. The written note C will sound as an A. Music is written a minor 3rd higher than it actually sounds, so concert pitch is a minor 3rd lower.

written
sounds

When transposing by a minor 3rd, the distance between the original and transposed notes is three semitones. If the original note is in a space, the transposed note will also be in a space. Line notes will remain as line notes.

When the music contains accidentals these will be attached to the same notes, but might not be the same type of accidental as in the original. This the same melody shown three ways: at concert pitch, for trumpet in Bb written pitch (a major 2nd higher), and for clarinet in A written pitch (a minor 3rd higher).