The didjeridoo, or yadaki , an invention of Aborigine tribes indigenous to the Australian continent, is a wooden tube musical instrument which is perhaps the one of the oldest of all musical instruments. Classic Aborigine didjeridoos are not made so much as they are chosen from small, standing trees which have been hollowed out by ants. A didjeridoo maker can determine if the trunk is hollow by listening to the sound produced by tapping on the tree trunk. When a suitable tree is found, it is cut down, the ends are smoothed, and a mouthpiece is formed on one end using bees wax or resin. Not all Aborigine tribes have a tradition of playing the didjeridoo, and in the tribes which do maintain the tradition, not all people play.
Many tribes limit didjeridoo playing to men and boys, though in some tribes, women also play.
This gender dominance in didjeridoo players is a hard and fast rule in some groups, while in other groups it is similar to the gender distinction apparent in pro football fans. Instruction usually consists of being given a didjeridoo and told to go off into the bush and let the didjeridoo do the teaching. This method works, but requires a lot of trial and error and a nearby Australian outback. The didjeridoo is almost unique in the world of music in its use of a technique called circular breathing . Circular breathing allows the player to breath while producing continuous sound.