How to Transpose for B-flat Instruments
B-flat instruments are the most common transposing instruments in the orchestra and concert band. When a Bb instrument player reads a written C, the concert-pitch note that sounds is Bb — a major second lower. This means that to write a part for a Bb instrument that sounds a given concert pitch, you must write the part a major second higher than concert pitch.
The Transposition Rule
- Instrument Key
- B-flat Instruments
- Interval
- Major 2nd (2 semitones)
- Direction
- Written is a Major 2nd (2 semitones) above concert pitch
Concert Pitch to Written Pitch
To convert concert pitch to written pitch for Bb instruments: go UP a major second (2 semitones). Add 2 sharps to the key signature (or remove 2 flats). Concert C major goes to written D major. Concert Bb major goes to written C major.
Written Pitch to Concert Pitch
To convert written pitch to concert pitch for Bb instruments: go DOWN a major second (2 semitones). Remove 2 sharps from the key signature (or add 2 flats). Written D major goes to concert C major. Written C major goes to concert Bb major.
Worked Key Examples
Concert: C major — Written: D major (2 sharps)
Concert C major (no accidentals). Bb instrument player reads D major (2 sharps: F# and C#). Every written note sounds a major second lower. Written D sounds concert C, written E sounds concert D, written A sounds concert G.
Concert: Bb major — Written: C major (no accidentals)
Concert Bb major (2 flats). Bb instrument player reads C major (no accidentals). This is the most comfortable key for most Bb instrument players — no key signature to read. Written C sounds concert Bb, written G sounds concert F.
Concert: Eb major — Written: F major (1 flat)
Concert Eb major (3 flats). Bb instrument player reads F major (1 flat: Bb). Remove 2 flats from the concert key signature to get the written key. Written F sounds concert Eb, written C sounds concert Bb.
Concert: G major — Written: A major (3 sharps)
Concert G major (1 sharp). Bb instrument player reads A major (3 sharps: F#, C#, G#). Add 2 sharps to the concert key signature. Written A sounds concert G, written E sounds concert D.
Tips and Common Mistakes
Quick tip: For Bb instruments, the written key always has 2 more sharps (or 2 fewer flats) than the concert key. A useful mnemonic: "B-flat instruments read sharp." The tenor saxophone uses the same Bb transposition as the soprano and Bb clarinet, but sounds an octave lower — account for the register difference when writing ensemble parts.
Use the circle of fifths to visualize key signature relationships. Each step clockwise on the circle adds one sharp; each step counter-clockwise adds one flat. B-flat Instruments transposition moves 2 steps clockwise (adds 2 sharps) on the circle.
Instruments in This Group
Transpose with Precision — Get Tunable.
Tunable's chromatic tuner shows exact Hz values in real time. Use Tunable to verify your transposition by comparing written and concert pitch frequencies for all 4 B-flat Instruments.
