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The Whole HornTransposition › Trombone
Transposition · Brass

What key is the trombone in?

Quick answer. The trombone is in C — it is a non-transposing, concert-pitch instrument. A written C sounds concert C. Nothing has to be worked out: when your band director calls “concert B♭,” the trombone reads and plays a written B♭. It is reading the same pitch as the piano, the flute and the oboe.

What that means on the page

A transposing instrument is one whose written notes do not match the concert pitch that sounds. The trombone is not one of them. Read a written C and the audience hears concert C — the two are the same thing.

Instruments that read at concert pitch are sometimes called “C instruments,” and they are the ones a pianist can read alongside without converting anything.

Concert pitch to what the trombone reads

For a concert-pitch instrument the table is the least interesting one in the band, and that is exactly the point — every row is the same note twice:

When the director says “concert ___,” the trombone reads and plays:
Concert pitch (sounds)Trombone reads
Concert B♭B♭
Concert E♭E♭
Concert FF
Concert CC
Concert A♭A♭
Concert GG
Concert DD

This is why the trombone is the instrument a director will ask to sound a tuning note or demonstrate a passage: what it plays is what everyone else has to match, with nothing to convert.

Why the trombone is written this way

The trombone reads at concert pitch in bass clef, so a written C is concert C. It is often called a B♭ instrument because its tubing is in B♭ and its slide positions are built on that harmonic series — but that describes the instrument, not the notation. The exception is British brass-band writing, where the tenor trombone is notated in treble clef as a B♭ transposing instrument sounding a major ninth lower.

Written range

The standard written range of the trombone is E2 to B♭4, written and sounding the same. That is the range parts are scored in and the range these pages and the app both use.

Why this matters for practice

The trombone reads at concert pitch, which makes it the reference the rest of the band tunes and transposes against. The fastest way to build fluency is to practise the twelve major scales in the instrument’s own written pitch, hearing each note as it truly sounds. See the full trombone fingering chart — every note with its written and concert pitch — or read the method behind mastering all twelve keys.

Frequently asked

What key is the trombone in?

The trombone is in C. It is a concert-pitch instrument, so a written C sounds concert C.

Is the trombone a transposing instrument?

No. Written pitch and sounding pitch are the same, so no transposition is needed to play from a concert-pitch part.

What does the trombone play for “concert B♭”?

A written B♭ — the same note the director names, because the trombone reads at concert pitch.

Can the trombone read piano music?

Yes, as far as pitch goes: piano music is written at concert pitch and so is the trombone part. Only the range and the clef need checking.

What is the range of the trombone?

The standard range is E2 to B♭4, written and sounding the same.

Practice every key in your instrument’s pitch.

The Whole Horn plays all twelve major scales in the trombone’s own pitch, with the fingering for every note.

Get the app → The full transposition chart

By Thomas Hornig — Henri Selmer Paris artist · Professor of Saxophone, Lebanese National Higher Conservatory of Music.
Related: Vibrato Practice — free vibrato trainer · Trombone fingering chart · The full band transposition chart · The method · Trombone range