Percussion
 

 Drums
Drums are an important part of any percussion section. Although their construction is 
simple, drums have many more uses than just keeping rhythm. In early Africa, for instance, 
drums were used as means to communicate. Most drums consist of material, such as calfskin, 
stretched over a hollow body. Hitting the drumhead causes vibrations which are amplified by 
the body's hollow chamber. Some drums, like the snare and bass drum, don't have a definite 
pitch. The drumhead can be tightened or loosened to make the drum sound higher or lower. 

The timpani, a.k.a. kettledrum, is one type of drum that does have a definite pitch. The 
timpani can be tuned by tightening the drum skin but also by using a pedal located at the 
bottom of the instrument. Because the timpani can play definite pitches, it can sometimes 
play simple ostinatos with other instruments in an orchestra. The timpani player has to be 
very good at tuning, because the timpani goes out of tune easily, especially in hot and 
humid weather. 



Xylophone 

The xylophone and it's cousins the marimba and the glockenspiel are percussion instruments 
with bars that produce definite pitches when struck. The xylophone and marimba have bars 
made of wood, but the xylophone has a tube under each bar to increase resonation while the 
marimba has a sound box. The glockenspiel is like a tiny xylophone except it's bars are made 
of steel. All xylophone type instruments are tuned chromatically to one or more octaves. 
They are played with mallets that have either hard heads for a bright sound or soft heads 
for a mellow sound. Xylophones are found all over the world, from the Netherlands to Mexico 
to China. 



Learn More... 

Percussion Instruments -- http://www.americaslibrary.gov/cgi-bin/page.cgi/sh/oddball/mallet_1