<P> A wind instrument is a musical instrument that contains some type of resonator (usually a tube), in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece set at or near the end of the resonator . The pitch of the vibration is determined by the length of the tube and by manual modifications of the effective length of the vibrating column of air . In the case of some wind instruments, sound is produced by blowing through a reed; others require buzzing into a metal mouthpiece . </P> <Ul> <Li> Using different air columns for different tones, such as in the pan flute . </Li> <Li> Changing the length of the vibrating air column by changing the length of the tube through engaging valves (see rotary valve, piston valve) which route the air through additional tubing, thereby increasing overall tube length, lowering the fundamental pitch . This method is used on nearly all brass instruments . </Li> <Li> Changing the length of the vibrating air column by lengthening and / or shortening the tube using a sliding mechanism . This method is used on the trombone and the slide whistle . </Li> <Li> Changing the frequency of vibration through opening or closing holes in the side of the tube . This can be done by covering the holes with fingers or pressing a key which then closes the hole . This method is used in nearly all woodwind instruments . </Li> <Li> Making the column of air vibrate at different harmonics without changing the length of the column of air (see natural horn and harmonic series). </Li> </Ul> <Li> Using different air columns for different tones, such as in the pan flute . </Li> <Li> Changing the length of the vibrating air column by changing the length of the tube through engaging valves (see rotary valve, piston valve) which route the air through additional tubing, thereby increasing overall tube length, lowering the fundamental pitch . This method is used on nearly all brass instruments . </Li>

Instruments that must be played with the mouth