Percussion is the act of striking an object with a sharp, quick blow. The blow may be delivered by the hand or some instrument especially designed for the purpose of striking the object.
More commonly, percussion is related to the production of musical tones or rhythms. Many musical instruments employ the principles of percussion. The drum is considered a percussion instrument and is used for keeping the tempo or "beat" of the music. Cymbals, tambourines, and castanets are other examples of the same type of percussion instrument. The piano and xylophone are percussion instruments also, but they are capable of producing melodies as well as keeping the tempo.
Along more purely scientific lines, percussion is used to describe a point on an object such as a PENDULUM. When a blow is delivered to exactly that point, it will cause rotation only around the place of suspension. This point is known as the center of percussion. An example of this effect is shown by a baseball and a bat. If the batter hits the ball directly on the center of percussion, there will be no shock transmitted to the batter's hands as would be the case if the ball were hit any other place on the bat.
