Concert pitch and written pitch
On a piano, a C is a C. On a B♭ clarinet, the player reads a C, fingers a C, and a B♭ comes out. The note that actually sounds is the concert pitch. The note on the player's page is the written pitch. They differ by a fixed interval for each type of instrument.
To find what sounds from what is written, go down by the instrument's interval. To write a part for the instrument from a concert score, go up by that interval, and move the key signature the same way.
The transposing instruments
| Family | Instruments | Reads C, sounds | Written is |
|---|---|---|---|
| B♭ | B♭ clarinet, B♭ trumpet, soprano sax, tenor sax (an octave lower) | B♭ | 2 half steps above |
| E♭ | alto sax, baritone sax (an octave lower), E♭ clarinet is the other way (written a minor 3rd below) | E♭ | 9 half steps above |
| F | French horn, English horn | F | 7 half steps above |
| A | A clarinet | A | 3 half steps above |
Some instruments change only the octave: guitar and double bass (sound an octave lower than written); piccolo (sounds an octave higher than written). The note names are unchanged, so these do not count as transposing for most purposes.
Non-transposing (concert pitch): piano, flute, oboe, violin, viola, cello, trombone, bassoon, voice.
Key signatures for transposing instruments
A band plays one tune in concert B♭ major (two flats). The trumpets read it in C major (no sharps or flats). The alto saxes read it in G major (one sharp). The horns read it in F major (one flat). Same sound, different page. Practise the notes, then the keys.
Related: the transpose drill moves notes by half steps, the chord transposer moves whole songs, and the key signature quiz keeps the signatures fast.
Frequently asked questions
What is a transposing instrument?
An instrument whose written music sounds in a different pitch from what the player reads. A B♭ clarinet player who reads and fingers a C actually produces a B♭. The part is transposed so that the player uses the same fingering across the whole family of instruments.
What is concert pitch?
The pitch that actually sounds, as a piano or flute would play it. A concert score shows every instrument at its sounding pitch; a player's part is written in the transposed pitch for their instrument.
Why do transposing instruments exist?
They let a player switch between sizes of the same instrument (soprano, alto, tenor and baritone sax) without learning new fingerings: the same written note uses the same fingering on all of them, whatever it sounds.
How do I find the written note for a B♭ instrument?
Go up a major 2nd from the sounding note. Concert C is written as D for a B♭ trumpet or clarinet. For the key signature, add two sharps (or take away two flats): concert B♭ major becomes C major.
How do I find the written note for an alto sax?
Go up a major 6th from the sounding note (the same as down a minor 3rd, an octave higher). Concert E♭ is written as C. For the key, add three sharps (or take away three flats).
Which instruments do not transpose?
Most orchestral instruments read in concert pitch: piano, flute, oboe, violin, viola, cello, trombone, bassoon and voice. Guitar and double bass sound an octave lower than written, and the piccolo an octave higher, but keep the same note names.