What a transposing instrument is
A transposing instrument is one whose written notes sound at a different pitch from the same notes on a piano. A B♭ clarinet reading a written C produces the pitch a piano calls B♭, a major second lower. The pitch that actually sounds is called concert pitch; the pitch on the player’s part is written pitch. The instrument’s name is the pitch it sounds when it reads C.
- B♭ instruments (clarinet, trumpet, soprano sax, tenor sax) sound a major second lower than written: written C sounds B♭.
- E♭ alto sax sounds a major sixth lower than written: written C sounds E♭. Baritone sax is a major sixth plus an octave lower.
- F horn sounds a perfect fifth lower than written: written C sounds F.
- To write a part for any of these from concert pitch, transpose up by the same interval and adjust the key signature.
Piano, flute, oboe, violin, trombone and most other instruments are non-transposing: the note on the page is the note that sounds. The transposing ones are mostly the wind instruments that come in families, clarinets, saxophones, trumpets and horns, and the convention exists for the player’s benefit, not the listener’s.
Why parts are written this way
Parts are transposed so that one set of fingerings serves a whole family of instruments. On every saxophone, from soprano to baritone, the fingering a player learns as “C” is the same fingering, even though each instrument produces a different concert pitch from it. Write every part so that that fingering is spelt C, and a player can pick up any saxophone and read without relearning the instrument.
The same logic holds for clarinets in B♭ and A, trumpets in B♭ and C, and horns. Historically the sounding pitch of an instrument depended on the length of its tube, and builders made them in the lengths that played best; the notation simply followed. The cost is paid by conductors, arrangers and anyone trying to play a clarinet part on a piano, who have to do the arithmetic the clarinettist never has to think about.
B♭, E♭ and F: which way each moves
The rule that covers every case: the instrument’s key name is the concert pitch that sounds when the player reads a written C. From that you can work out the interval and its direction. For the three common families the sounding pitch is always lower than written, so to prepare a part from concert pitch you transpose up.
B♭ instruments: clarinet, trumpet, soprano and tenor sax
Written C sounds B♭, a major second (one whole tone) lower. Written D sounds C, written G sounds F, written A sounds G. Tenor saxophone and bass clarinet sound a major second plus an octave lower, a major ninth. To write a B♭ part from concert pitch, move every note up a whole tone and add two sharps to the key signature (or take away two flats): concert B♭ major, two flats, becomes written C major, no sharps or flats; concert C major becomes written D major, two sharps.
E♭ instruments: alto and baritone sax
Written C sounds E♭, a major sixth lower. Written G sounds B♭, written A sounds C. Baritone saxophone sounds a major sixth plus an octave lower, a major thirteenth. To write an E♭ part from concert pitch, move every note up a major sixth and add three sharps (or take away three flats): concert E♭ major, three flats, becomes written C major; concert C major becomes written A major, three sharps. A quick check: the alto sax’s written C and the piano’s E♭ are the same sound. (The small E♭ clarinet is the one family member that sounds higher than written, a minor third up; it is rare outside bands and orchestras.)
F instruments: horn and cor anglais
Written C sounds F, a perfect fifth lower. Written G sounds C, written D sounds G. To write an F part from concert pitch, move every note up a perfect fifth and add one sharp (or take away one flat): concert F major, one flat, becomes written C major; concert C major becomes written G major, one sharp. Horn players also meet parts in E♭, D and other old crooks in orchestral music, but modern parts are written in F.
The interval is fixed; the direction depends on which way you are going. From written pitch to concert pitch (what the player actually sounds), go down by the interval. From concert pitch to written pitch (preparing a part), go up. Most mistakes on this subject are mistakes of direction, not of interval.
Why the part sounds wrong on the piano
A clarinet or trumpet part played at face value on the piano comes out a whole tone too high; an alto sax part comes out a major sixth too high; a horn part a fifth too high. The tune is recognisable, because the intervals between the notes are unchanged, but it is in a different key from the recording, and if anyone plays the accompaniment alongside you the result clashes on every note.
Two things follow. First, a student who checks a clarinet part against a piano by playing the written notes will think the part, or the piano, is out of tune, when both are fine. Second, the key signature on a transposed part is not the key of the piece: a clarinet part in D major belongs to a piece in concert C major. If you ever need to know what key a band piece is in, look at the flute or piano part, or the score, which are at concert pitch.
A worked example
A tune in concert B♭ major starts on the notes B♭, C, D, F. Prepared for B♭ trumpet, every note moves up a major second: C, D, E, G, and the key signature changes from two flats to none. Prepared for alto sax, every note moves up a major sixth: G, A, B, D, with a key signature of one sharp (G major). Prepared for horn in F, every note moves up a perfect fifth: F, G, A, C, with a key signature of one flat (F major).
Now check each one the other way. The trumpet player sees C and sounds B♭; the sax player sees G and sounds B♭; the horn player sees F and sounds B♭. Three different pages, one concert note. That is the whole system. If you want to confirm your arithmetic on any part, take its first note, go down by the instrument’s interval, and you should land on the concert pitch the flute or piano part shows at the same spot.
Beginner mistakes
- Transposing the wrong way. Going down when preparing a part, or up when working out what sounds. Fix: remember that written C on a B♭ instrument sounds B♭, which is lower; so concert-to-written is always up for these three families.
- Reading the part’s key signature as the key of the piece. A clarinet part in D is a piece in C. Fix: use the concert-pitch parts or the score to name the key.
- Forgetting the octave on tenor and baritone sax. A tenor sax written C is the B♭ a major ninth below, not the one a tone below; a baritone written C is the E♭ a major thirteenth below. Fix: transpose the interval first, then drop an octave for the big saxes.
A two-minute drill
- Name the intervalSay the three families aloud with their intervals: B♭ down a major second, E♭ down a major sixth, F down a perfect fifth. Twenty seconds. The direction is always down from written to sounding.
- Written to concertPick five random written notes and say what each sounds on clarinet, then on alto sax, then on horn. Sixty seconds. Use a keyboard if you have one to check.
- Concert to writtenTake a four-note tune you know at concert pitch and say the written notes a trumpet part would show. Forty seconds. Up a whole tone every time.
Hear your part as it sounds
Reading about transposition is one thing; hearing your own part is the thing that makes it make sense. Photograph the part in Sheetly and press play, and you hear the notes as they are written; choose a clarinet, saxophone or other instrument sound so that the part sounds like your instrument rather than a piano. For learning the shape, the rhythm and the hard bars that is exactly what you need, and you can loop a passage and slow it down. Then ask the coach what concert pitch the note in bar 12 is, and get an answer about that bar. Photograph it, hear it, understand it, practise it. More on hearing your part on a different instrument.
Hear the part on your stand.
Photograph it, press play, pick an instrument sound, loop the hard bars at a slower tempo, and ask the coach what a note sounds at concert pitch. Free to download on iPhone and iPad.
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When you get stuck
Sheetly is the only iPhone and iPad app we know of where the AI coach has read the actual notes of the page you photographed, so a question about bar 12 gets an answer about your bar 12. With a transposed part, the question is usually “what does this actually sound”, and the coach can answer for the note in front of you.
Ask Sheetly: a coach that has read your score
Not a chatbot bolted onto a music app. The coach has the actual notes of the page you just photographed, so you can ask about your bar 12 and get an answer about what is written in it.
We know of no other sheet-music scanner that does this. Every other tool hands you a transcription and stops.
Free to download · iPhone and iPadQuestions
What is a transposing instrument?
A transposing instrument is one whose written notes sound at a different pitch from the same notes on a piano. A B♭ clarinet reading a written C produces the pitch a piano calls B♭. The part is written this way so the player’s fingerings stay the same across the whole family of instruments; the sounding pitch is called concert pitch, the notes on the part are written pitch.
Is a B flat clarinet part written higher or lower than it sounds?
A B♭ clarinet part is written higher than it sounds, by a major second (one whole tone). A written C sounds B♭, a written D sounds C, a written G sounds F. The same is true of B♭ trumpet and soprano sax; tenor sax is also a B♭ instrument and sounds a major second plus an octave lower than written. To write a B♭ part from concert pitch, transpose up a major second.
What does an alto sax sound when it plays a written C?
An alto saxophone playing a written C sounds E♭, a major sixth lower than written. Alto sax is an E♭ instrument. Baritone sax is also in E♭ and sounds a major sixth plus an octave lower. To write an alto sax part from concert pitch, transpose up a major sixth and add three sharps (or remove three flats) from the key signature.
Why does my clarinet part sound wrong on the piano?
Because a clarinet part is written a major second higher than it sounds. If you play the written notes on a piano you hear the tune a whole tone too high, and against a recording or an accompaniment it clashes. To hear what the clarinet actually plays, play every note on the piano one whole tone lower than written, or have the part played back a whole tone lower.
What is concert pitch?
Concert pitch is the actual sounding pitch of a note, the pitch a piano, flute, violin or oboe would play from that note on the page. Non-transposing instruments read at concert pitch. Transposing instruments read written pitch, which differs from concert pitch by a fixed interval: down a major second for B♭ instruments, a major sixth for E♭ alto sax, a perfect fifth for F horn.
Which direction does a French horn transpose?
A horn in F sounds a perfect fifth lower than written: a written C sounds F, a written G sounds C. To write a horn part from concert pitch, transpose up a perfect fifth and add one sharp (or remove one flat) from the key signature. Cor anglais is also an F instrument and transposes the same way.