Wind instruments generate a sound when a column of air is made to vibrate inside them. The frequency of the wave generated is related to the length of the column of air and the shape of the instrument, while the tone quality of the sound generated is affected by the construction of the instrument and method of tone production. The group is typically subdivided into :Woodwind instruments, such as the clarinet, oboe and flute,Brass instruments, such as the trumpet, trombone and French horn.