Brass Instrument Sound Production

Different notes are produced on brass instruments by causing the air to travel different distances before escaping through the bell of the instrument. There are several different ways to cause the air to travel the extra distance. Valves and slides are very common in brass instruments. When valves are pushed down (or slides are moved out) this causes the air to travel a longer distance. The other way brass players can change notes is by changing the firmness of their lips. To play low notes on a brass instrument the lips must be relatively relaxed, and for high notes they must be much firmer.