Part of our guide to transposing a song to any key.
If a trumpet and a piano both read the same written C, they do not play the same note. The trumpet is a transposing instrument: its written music sounds at a different pitch than it looks. That single fact is behind most of the confusion in writing parts for a band or an orchestra, and once you see the pattern it is simple. This guide explains what makes an instrument transposing, why it works that way, and gives a full chart of which instruments sit in B-flat, E-flat, F, and concert pitch.
What a transposing instrument is
A transposing instrument is one whose written note and sounding note are different. The instrument is named for the pitch that comes out when the player reads a written C. Play a written C on a B-flat trumpet and you hear a concert B-flat; on an E-flat alto saxophone you hear a concert E-flat; on an F horn you hear a concert F. Concert pitch is simply the actual sounding pitch, the pitch a piano plays, so a concert-pitch instrument like the flute or the piano reads exactly what it sounds. The general idea of moving music between keys is covered in what is transposition; this page is about the instruments that force you to do it.
Why transposing instruments exist
The main reason is consistent fingering across a family. Every saxophone, from soprano to baritone, is fingered the same way, so a player can move between them and a written C always falls under the same fingers, even though the pitch that sounds is different on each one. The same holds for the clarinet family. A second reason is range: naming an instrument in a transposing key keeps a very high or very low instrument readable on a normal staff instead of drowning in ledger lines. The cost of all this convenience is that whoever writes the part has to transpose it into the instrument's reading key first.
The full transposing instrument chart
Here are the common instruments grouped by key, with the interval you move concert-pitch music up by to write each part.
| Key | Instruments | Write the part up by | Guide |
|---|---|---|---|
| B-flat | Trumpet, clarinet, soprano sax, cornet, flugelhorn | Major 2nd | Trumpet, clarinet |
| B-flat (lower) | Tenor saxophone | Major 9th (octave and a 2nd) | Saxophone |
| E-flat | Alto saxophone, baritone saxophone | Major 6th (octave and a 6th for baritone) | Saxophone |
| F | French horn, English horn | Perfect 5th | French horn |
| C (concert pitch) | Flute, oboe, bassoon, piano, violin, trombone | No change | Not transposing |
One worth flagging: the small E-flat sopranino clarinet is the unusual case that sounds higher than written rather than lower, so it is the exception to the pattern above. For the everyday band and orchestra instruments, the four rows of transposers cover what you will meet.
Octave-transposing instruments
A few instruments transpose only by an octave, written higher or lower than they sound purely to stay off ledger lines. The piccolo sounds an octave above its written notes; the guitar, the bass guitar, and the double bass sound an octave below; the glockenspiel sounds two octaves above. These are simpler than the B-flat and E-flat instruments because the letter names do not change, only the octave, so they rarely cause the key confusion that the named transposers do.
Writing a part in the right key
Once you know an instrument's interval, writing the part means moving the concert-pitch music up by that amount and adjusting the key signature to match. Doing it by hand across a whole part is slow and easy to get wrong. The faster route is to start from an editable score: transcribe the recording with Songscription, set the instrument's reading key, and export a part that is already transposed. The per-instrument guides for trumpet, clarinet, saxophone, and French horn walk through each one, and the full workflow lives in the transposition guide.
Get a part in the right reading key
Upload a recording, get an editable score, and export a part already transposed for the instrument that is playing it. The free tier is enough to try it on one song.
Related guides
- The concept: what is transposition and the transposition guide.
- By instrument: trumpet, clarinet, saxophone, and French horn.
- For a singer: transpose a song to fit your voice.
Frequently Asked Questions
What is a transposing instrument?
A transposing instrument is one whose written music sounds at a different pitch than written. When the player reads a C, a different concert pitch comes out. The instrument is named for the pitch that sounds when it plays a written C: a B-flat trumpet sounds a B-flat, an E-flat alto saxophone sounds an E-flat, an F horn sounds an F. To write a part that sounds correct, you transpose the concert-pitch music into the instrument's reading key.
What instruments are in B-flat, E-flat, and F?
The common B-flat instruments are the trumpet, the soprano and tenor saxophones, the clarinet, the cornet, and the flugelhorn. The common E-flat instruments are the alto and baritone saxophones. The F instruments are the French horn and the English horn. Concert-pitch instruments, which do not transpose, include the flute, oboe, bassoon, piano, violin, and trombone.
Why do transposing instruments exist?
Mostly so players can switch between instruments in the same family without relearning their fingerings. Every saxophone is fingered the same way, so a written C produces each instrument's home note even though the actual pitch differs. It also keeps very high or very low instruments on a readable staff. The tradeoff is that anyone writing for these instruments has to transpose the part into the right reading key.
How do I write a part for a transposing instrument?
Move the concert-pitch music up by the instrument's interval: a major second for B-flat instruments, a major sixth for E-flat instruments, and a perfect fifth for F instruments. Doing it by hand is error-prone, so the faster route is to start from an editable score: transcribe the recording with Songscription, set the instrument's reading key, and export a part that is already in the right key.
The fastest way to put this to use is on a real song. Upload a recording with Songscription and export a part in the reading key your instrument needs.
