The Brass Quartet Transposition Trap
A candidate is arranging a four-part chorale in A♭ major for a brass quartet: Bb trumpet 1, Bb trumpet 2, horn in F, and trombone. The chorale's ranges are: soprano A♭4–F5, alto D♭4–B♭4, tenor A♭3–E♭4, bass D♭2–A♭3. The candidate's draft assigns soprano to trumpet 1, alto to trumpet 2, tenor to horn in F, and bass to trombone. The candidate has written the trumpet parts in treble clef at sounding pitch (i.e., as if they were concert-pitch instruments) and the horn part in bass clef at sounding pitch. The examiner flags two problems: (1) the trumpet parts will sound a major second lower than written, so the soprano's F5 will sound E♭5, not F5; (2) the horn part in bass clef at sounding pitch will be read by the horn player as a perfect fifth lower than written, producing a tenor line that is a perfect fifth too low. The candidate argues that the players can transpose at sight. The examiner must decide whether to require a properly transposed score and how to distribute the voices to avoid range and balance problems.
1. Identify the correct written transpositions for each instrument (trumpet in Bb, horn in F) and show the written pitch for the soprano's F5 and the tenor's A♭3.
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A Bb trumpet sounds a major second lower than written, so to sound F5 the trumpet must read G5. A horn in F sounds a perfect fifth lower than written, so to sound A♭3 the horn must read E♭4. The candidate's draft, which writes the trumpet at sounding pitch, would produce E♭5 instead of F5, and the horn's bass-clef sounding-pitch A♭3 would be read as a written A♭3 and sound D♭3, a perfect fifth too low. The corrected score should therefore have trumpet 1 in treble clef written G5, trumpet 2 written a major second above its sounding alto line, and horn in F in treble clef written a perfect fifth above its sounding tenor line. The trombone reads at concert pitch and needs no transposition.
2. The horn's written range: if the tenor line goes down to A♭3, what written note would the horn need to play, and is that within a comfortable range? If not, propose an alternative distribution of voices.
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To sound A♭3, the horn must read E♭4 in treble clef. That is a comfortable middle-register note for the horn, so the tenor line itself is playable. The problem is not the range but the candidate's clef and transposition error: writing A♭3 in bass clef at sounding pitch makes the player read a written A♭3, which sounds D♭3 and is too low. Once the horn part is correctly written in treble clef at E♭4, the tenor line is fine. If the candidate wanted a darker blend, the alto line could be given to the horn and the tenor to trumpet 2: the alto's D♭4–B♭4 would require horn written A♭4–F5, which is higher and less comfortable, so the original distribution is preferable. The examiner should require correct transposition, not a redistribution.
3. Explain why 'the players can transpose at sight' is not an acceptable solution for an exam arrangement, and what the candidate should do instead.
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Sight transposition is not acceptable because an exam arrangement is assessed on the written score and on the players' ability to read it as notated. Asking brass players to transpose at sight introduces uncertainty, may cause wrong octaves or missed accidentals, and is not standard practice for a prepared quartet score. The candidate should instead produce a properly transposed score: trumpet 1 and trumpet 2 in Bb, written a major second higher than sounding; horn in F in treble clef, written a perfect fifth higher than sounding; trombone at concert pitch. The candidate should then check ranges and balance: the soprano's written G5 for trumpet 1 is high but playable, so a moderate dynamic marking is advisable; the horn's written E♭4 for the tenor is comfortable. The score should be clear, with correct clefs and key signatures for each transposing instrument.