The Orchestral Brass Section
- Trumpet (Bb) (treble clef)
- French horn (F) (treble clef, also sometimes bass)
- Trombone (bass clef, also sometimes tenor/treble)
- Tuba (bass clef)
In a score, horns are at the top of the brass section, followed by trumpets, trombone and tuba. Trumpets in Bb and horns in F are the modern standard, but in the past brass instruments could be in any transposition key.
Classical orchestra: small number of trumpets/horns. Romantic orchestra: large brass section.
In the Classical period (c.1750-1830), trumpets and horns did not have valves or pistons. They were simple brass tubes folded round on themselves. This means an individual instrument was restricted to just eight or nine notes (produced by blowing with increased air pressure, as the pitch ascends).
The non-transposing trumpet in C was generally limited to this selection of notes:
Horns worked in the same way, but could play one extra lower note. Players learned this small series of notes, and did not need to learn any others.
Notice that the first five notes all belong to the tonic triad of the key of the instrument. This meant that trumpets and horns were very good at playing arpeggios, but were not able to play full scales.
If a composer wanted the trumpets/horns to play notes which are not available on the C instrument, they would instruct the player to use a longer/shorter tubed instrument so that the required notes were available. Increasing the length of the tubing will produce a lower series of notes, and shortening the tubing will produce a higher series, but the intervals between each note will always remain the same. The player would read from transposed music, so that the series of notes used in the music was always the same, whatever the size of the instrument.
For example, a trumpet in Bb (slightly longer than a trumpet in C) will sound these notes, which are all a major 2nd lower than the C instrument:
But for the brass players, they would simply read the written pitch for a C instrument, no matter what size instrument they were using.
For this reason, all brass parts in the Classical era were written with no key signature.
If you look at a score of a Classical era symphony (e.g. by Mozart or Haydn) you will see that the brass parts are always “in C”, and that the required pitch of instrument is written at the start of the score.
Here is an example from Haydn’s Symphony no.58, 1st movement. The key of the music is F major, so horns in F are used, and their music is written in C. The sounds made by the horns will be a perfect 5th lower than written.
Modern brass instruments are capable of playing all the notes in the chromatic scale, so only one instrument is needed. Trumpets are normally pitched in Bb and horns are in F, although some professional players might still own instruments in other keys.