Brass Instruments - Start Here for Science, Math and Maintenance

Brass Instruments - Start Here for Science, Math and Maintenance

This article provides basic knowledge for all brass players, and can be a helpful starting point for assignments and projects in other subjects. 

Terminology

To develop a common understanding, it is helpful to know the terms used. We all do better when we know what the words mean.

Low brass includes baritones, euphoniums, marching baritones, tubas, and sousaphones.

High brass includes French horns, cornets, and trumpets.

Length

All brass instruments can be understood as simple tubes through which the player blows air. The length and size of the tube determines its pitch. High brass instruments are made with shorter, smaller tubes. Low brass instruments are made with longer, larger tubes.

The total length of tubing used in cornets and trumpet is about 6.5 feet long.

French horn tubing is about 18 feet long.

The tubing length of trombones, baritones, and euphoniums is about 9 feet long and can be longer.

Tubas and sousaphones are about 13 - 18 feet in length.

Bore

The length of each particular instrument is interesting, but the size of the tube matters too. Bore is a term used to describe brass instruments and refers to the inner diameter of the tubing. Put another way, the bore is the size of the tube.

Bore is measured to three decimal places, in thousandths of an inch. For this reason, bore is less of a consideration for beginners than for experienced players.

The French horn is the longest tube, but actually includes two sets of slides. It is two horns in one with a valve configured to switch between the two sets of slides. The French horn is also a conical instrument like an ice cream cone. The tubing is a long cone with a bore which grows in diameter from the small lead pipe to the large bell.

Like a French horn, the cornet, euphonium, and sousaphone are conical, which means the bore is tapered to get larger from the mouthpiece to the bell.

The trumpet, baritone, and tuba are cylindrical which means the bore size is the same through the body of the instrument and just the bell section is tapered larger.

Components

High and low brass instruments all have similar components including the mouthpiece, receiver, lead pipe, valves, slides, water keys, bows, branches, and bells.

Mouthpieces

Brass mouthpieces are made from a solid piece of brass which is milled to have a rim, cup, throat, shank, and back bore. A brass mouthpiece serves as a ‘funnel’ to get air from the player through the instrument. The shape of the funnel can make a difference in the sound produced. Band directors prefer to have the players using the same size funnel to create a consistent sound.

Common low brass mouthpieces sizes are the Bach 6 ½ AL for trombone, and the Bach 24 for tuba. It is a good idea to get a mouthpiece brush and a mouthpiece pouch for low brass players. Keeping the mouthpiece in a pouch helps keep it clean and protects it from damage in case it is accidentally dropped or falls out of a backpack. 

Trombones, baritones and euphoniums may be either ‘large bore’ or ‘small bore’. While the size of the mouthpiece is the same, the ‘shank’ which connects to the instrument must match. A large bore instrument requires a large shank mouthpiece.

Oil

Oil is for valves. Brass instruments may have either piston valves or rotary valves. 

Piston valves are the most common and move up and down on a spring inside the valve cylinder. Cornets, trumpets, baritones, euphoniums, and tubas use piston valves. 

Rotary valves turn in a circle and are sealed inside a rotor housing. French horns, trigger trombones, and concert tubas have rotary valves.

Valve oil is intended for piston valves. Rotary oil is intended for rotary valves. Rotary oil with a needle style applicator bottle is more effective at getting the oil where it needs to go. The difference between valve oil and rotary oil is a matter of viscosity - the thickness of the oil. Rotary oil is generally thinner or 'lighter' than valve oil which is slightly thicker or 'heavier'.

Slide Grease

Slide grease is for slides. Keeping the instrument slides lubricated is the best way to avoid costly repairs. 

The most common repair for brass instruments is to remove a stuck mouthpiece. Mouthpieces which have damage to the shank often get stuck. 

The second most common repair for brass instruments is to free stuck slides. Dry slides stick and eventually will corrode together. If your instrument slides do not move, they need slide grease.

*It is very easy to damage the instrument if you apply too much force trying to remove stuck slides. 

We have special tools and experience in our repair shop to keep your instrument in working condition.

Cleaning Brushes

A clean instrument is a happy instrument and special brushes make it easy to clean your instrument

  1. Get a mouthpiece brush. Keep your mouthpiece clean with a quick brush stroke to avoid unpleasant odors and help your valves stay smooth.
  2. A flexible cleaning snake will help clean the inside of slides and reach around the curves too.
  3. Valve casing brushes provide a quick way to keep your valves working smoothly

Brass instruments can be cleaned with soap, warm water and a polish cloth or towel. Warm water works better to remove oil and grease. Be sure to rinse the soap and dry the pieces. Oil valves and grease slides before reassembly.