Source: http://en.wikipedia.org/wiki/Xylophone.htm
The xylophone consists of a series of wooden bars of different dimensions, producing different pitches. The bars are struck with sticks, hammers or mallets. Different woods from different species of trees have different densities, producing different frequencies when hit, while the dimensions of the bars also play a role in the resulting soundwave.
Traditional xylophones do not have soundboxes. Modern manufactured xylophones typically have one sound box for all the bars. Traditional xylophones with individual soundboxes for each bar are known as marimbas, while xylophones with metal bars are known as glockenspiel.
Source: http://en.wikipedia.org/wiki/Xylophone.htm
Source: http://en.wikipedia.org/wiki/Xylophone.htm
http://www.youtube.com/watch?v=BHP5xjBP-9I