Despite its name the brass family is a group of instrument that has more in common with the way they produce sound, rather than the material they are built with. Common instruments like the flutes and saxophones in the woodwind family are made out of brass, by contrast instruments like the serpent (an ancestor of the tuba) are mostly built from wood. The instruments that usually make up this section nowadays are the horn, trumpet, tenor trombone, bass trombone, and tuba.
As with the woodwind section, it is not until the beginning of the Classical period that the brass section starts to evolve into the makeup we know today. Before that, in the Renaissance and Baroque era, brass instruments were only used in particular works, especially in operas, to give a unique color to the music. Examples of this include “L’Orfeo” by C. Monteverdi and “Israel in Egypt” by G. F. Handel.
From the Classical period –or even the late Baroque period– there was a gradual growth of the brass section. A pair of horns and oboes were commonplace in orchestras in those days, complemented with a pair of trumpets in the bigger symphonies. Trombones, as well as the antecessors of the tuba (the serpent and then the ophicleide), were incorporated from the end of the Classical period and beginning of Romanticism.
But the breaking point for this section occurred with the development of valves in the beginning of the 19th century, which was widely adopted by orchestras and musicians by the second half of the century. With this system, a new world of possibilities opened for this group of instruments, which lead to more complex parts and important roles at the end of the 19th century and into the 20th century.
To realize how big this milestone was, we need to understand how a brass instrument produces sound. All brass instruments’ sound starts with the vibration of the lips of the player, which is transmitted to the pipe, making it resonate at a certain frequency according to the speed of the airflow, lip and mouth configuration, and length of the tube.
Natural brass instruments (without valves) have only a single fixed length of pipe so only overtones of the series (starting from the 2nd partial) can be produced by adjusting the airflow and lip and mouth configuration. This gives the player a limited amount of possibilities, confining him or her to play just in the key the instrument is tuned in. To get around this, players have either the option of using different instruments in different keys to change between pieces or movements, or using Crooks, a little segment of tubing that, added to the main pipe, adjusts its total length. Since both of these methods require a considerable amount of time, valves revolutionized brass instrument’s playability, allowing for the first time the performance of complex chromatic passages.
1. Valve bypassed: the air goes through the main pipe.
2. Valve not bypassed: the air goes through the additional piping.
Brass instruments are divided into two categories depending on the shape of its bore:
- with cylindrical bore: have the same diameter throughout their whole pipe, only flaring right at the end, just before the bell. Brass instruments with this type of pipe have a more focused, bright, and “brassy” sound. All trumpets, trombones, and the cimbasso have cylindrical bores.
- with conical bore: have a pipe that changes diameter throughout its length, starting smaller right after the mouthpiece, and widening until the bell starts. Brass instruments with this type of pipe have a rounder, slightly duller, darker, and less “brassy” sound than brass instruments with a cylindrical bore with similar range. The French horn, all tubas, as well as the flugelhorn, Wagner tuba and euphoniums have conical bores.
There is also another element that participates in the production of the sound of brass instruments, the mouthpiece. Just like the woodwinds, it has a lot to do with the sound which we identify with a particular instrument.
In the brass family, there are two types of mouthpieces:
- Semi-spherical: produce a more focused and brighter sound. All brass instruments, except the French horn and Wagner tuba, use semi-spherical mouthpieces.
- Conical: produce less defined sound. Only the French horn and the rare Wagner tuba use this type of mouthpiece.
Mouthpieces also vary in size and depth. Instruments with a lower range use a larger and deeper mouthpiece, as opposed to higher instruments, which don’t need as much room for the lips to vibrate.
Mouthpieces of: 1. French horn, 2. Trumpet, 3. Tenor trombone, 4. Tuba and cimbasso
The brass section currently has a makeup of around 4 to 8 French horns, 2 to 4 trumpets, and rarely anything different than 3 trombones and 1 tuba. Additionally, the cimbasso is a very popular instrument among the biggest budget film scores and Italian orchestras, but hard to find in most symphonic orchestras.