Percussion instruments, played
by either being struck or shaken, include members that are the oldest
instruments in the world. Different types of drums, for example, have
been in existence for thousands of years. Two principal divisions exist
in the percussion family: the untuned instruments like the bass drum and
the timpani that produce a sound when struck but no specific definite
tone; and the tuned instruments like the xylophone, the bells, and the
triangle, which have a recognizable pitch.
Most of the instruments are made of either wood or metal.
Drums have stretched animal skin fitted over the metal or wooden frame
that, depending on the tension of the skin, produces a deep resonant tone.
In general, percussion instruments act as the rhythm section of the orchestra.
The snare drum has skin over both ends, creating a rattling sound. Most
percussion instruments were used for military purposes (to call men into
action) until the 17th century when composers began using them in their
works. Beethoven was one of the first to integrate them wholeheartedly
into his symphonies.
Other untuned percussion instruments that are
normally used in orchestras include the cymbal and the gong, both of which
are mainly used at climactic moments in the musical score. The sweet,
high pitch sounds of tuned instruments like the bells have normally been
used in orchestras to add a 'celestial' motif to the compositions.