Didgeridoo - Didjeridu - Yidaki
The World's Oldest Woodwind Instrument

The didgeridoo (also known as didjeridu, didj, didge or yidaki) was first used some 70,000 to 100,000 years ago by the Australian Aboriginal. It is very much a spiritual instrument and closely associated with the Aboriginal Dreamtime. It is traditionally played at corroborees, the ceremonial dances of the Australian Aboriginal, and is accompanied by the click sticks, clapped boomerangs and the chanting of the tribe.
The didgeridoo is a fairly straight section of eucalyptus tree trunk or branch which had been hollowed out by termites. They are usually 1 to 1.5 metres long, although some special ceremonial didgeridoos can be up to 2.5 metres and represent the Rainbow Serpent. Ideally they have a taper which opens out to a flare, not unlike a trumpet. However, unlike a trumpet, which is played with tightly pursed lips, a didgeridoo is played with loose lips ... the type of sound you make when 'blowing a raspberry' or like the sound a horse makes.
There are actually many different tribal names for the didgeridoo, besides those above, and as many stories about its origin. The most likely story I have heard goes something like this;
A long, long time ago, while the men of an Aboriginal tribe were out hunting for food, they discovered that hollow trees and logs often harbored small animals. One day, one of the men blew into a hollow log to possibly dislodge a small animal and was so surprised by the sound it made, he kept blowing. When he looked up, all the other men were clapping and dancing to the rhythm.