Brass instrument an organ or a choir. Brass instrument A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called "labrosones", literally meaning "lip-vibrated instruments". There are several factors involved in producing different pitches on a brass instrument. Slides, valves, crooks (though they are rarely used today), or keys are used to change vibratory length of tubing, thus changing the available harmonic series, while the player's embouchure, lip tension and air flow serve to select the specific harmonic produced from
Vibrato and shaping of the lips and facial muscles, essentially repeatedly "bending" the note. This is called lip-vibrato, and is probably the most commonly used technique of vibrato on a lower brass instrument. It is also known to give the best sound and timbre on a brass instrument and is encouraged in upper-level or militaristic style brass ensembles. Players may also produce vibrato by gently shaking the horn which varies the pressure of the mouthpiece against the lip. This is referred to as hand vibrato. It is more favored in higher brass, but does not possess the same sound quality as