Bamboo is used for various purposes and there are 1500 documented uses of Bamboo. Its also used as a wind and light breaker. Bamboo's are usually planted in rows and the clumps are pretty dense, the winds that blow get partially blocked in the clump and hence create a sound when the caress the stems, branches and leaves and this creates the bamboo music. Its the rustling of the leaves and its very soothing, its said that Lord Buddha used to meditate in a bamboo forest.
Notice that the stiffest tree is most easily cracked, while the bamboo or willow survives by bending with the wind.
Bruce Lee