valve
[English]
On a brass instrument, a valve is a mechanism that, when in use, directs the air column along additional tubing inside the instrument, thus producing a different fundamental and harmonic series.
Most modern valved instruments employ similar valve systems which results in the same patterns of valve combinations to alter a pitch. For example, depressing the first valve will normally result in lowering the original pitch by one step, or the interval of a second. The table below shows the valve combinations of a typical valved instrument and the resulting pitch alterations. It should be noted that the addition of the fourth valve became common in the mid-20th century to help produce better intonation with the third valve combinations that tended to be "out of tune" or having poor intonation (especially the 1st & 3rd valve combination). Valves can be created in a rotary or piston configuration.
Valve and Pitch Relationships
| Valve Combinations | Pitch Lowered |
| 2nd Valve | 1/2 step |
| 1st Valve | 1 full step |
| 3rd Valve | 1 & 1/2 steps |
| 1st & 2nd Valves | 1 & 1/2 steps |
| 2nd & 3rd Valves | 2 full steps |
| 1st & 3rd Valves | 2 & 1/2 steps |
| 1st, 2nd, & 3rd Valves | 3 full steps |
| 4th Valve Combinations | |
| 4th Valve | 2 & 1/2 steps |
| 2nd & 4th Valves | 3 full steps |
| 1st & 4th Valves | 3 & 1/2 steps |
| 3rd & 4th Valves | 4 full steps |
| 1st, 2nd, & 4th Valves | 4 full steps |
| 2nd, 3rd, & 4th Valves | 4 & 1/2 steps |
| 1st, 3rd, & 4th Valves | 5 full steps |
| 1st, 2nd, 3rd, & 4th Valves | 5 & 1/2 steps |
See trumpet-valve-air-flow in the Appendix.
See Also
[English] rotary valve[English] piston valve
Share
Tweet
Last Updated: 2016-05-04 13:29:27