B-flat Trumpet
Quick Facts
- Instrument Key
- B-flat
- Transposition Interval
- Major 2nd down
- Written C sounds as
- Bb3
- Instrument Family
- brass
- Instrument Page
- B-flat Trumpet on Tunable
Written vs. Sounding Pitch — Frequency Table
Each row shows a written pitch (as it appears in the score) and the concert-pitch note that sounds when played. Frequencies are equal temperament at A4=440Hz.
Key Signature Conversion Table
When the conductor names a concert key, this table shows what key signature the B-flat Trumpet player reads. The player reads the written key; the audience hears the sounding key.
Practical Scenarios
Reading an Orchestral Part in a Score
A full score shows "Trumpet in Bb." When the score shows a written C5, the Bb trumpet sounds Bb4. The conductor sees concert pitch in the score; the player reads the transposed part.
Jazz Lead Trumpet: Concert Key of Eb
The big band is playing in Eb major (concert pitch). The lead trumpet player reads F major (two sharps) — each note a major second higher than concert pitch. A written G sounds as F, a concert-pitch Eb sounds as written F.
Section Tuning: Matching the Piano
The pianist plays concert pitch A4 (440 Hz). For the Bb trumpet to match, the player tunes their written B4 — a major second above A — so the sounding pitch matches the piano's A4 (440 Hz). Written B4 (493.88 Hz on trumpet) sounds as A4 (440 Hz) concert.
Why Does the B-flat Trumpet Transpose?
The B-flat trumpet became the standard orchestral trumpet in the late 19th century, replacing the natural (valveless) trumpet in F. The transposition to Bb reflects the instrument's natural harmonic series: the open tube resonates at Bb, so the player's written C produces a sounding Bb. Before valves were invented (c.1815), natural trumpets were built in the key of the piece — a different trumpet for each key. The modern Bb trumpet with three valves can play all pitches chromatically while reading in Bb transposition.
Tune Your B-flat Trumpet with Precision — Get Tunable.
Tunable's chromatic tuner shows exact Hz values in real time. Tune to equal temperament A4=440Hz or explore all 16 temperament systems.
Related Instruments
How to Transpose for B-flat Instruments
All Transposing Instruments · Circle of Fifths · Keys Reference · Temperament Systems