Species of Eucalyptus number in the hundreds but only about a dozen species are used for didgeridoo making. The Eucalyptus is naturally hollowed out by termites whose nests abound in the millions in Australia. It takes at least a year for the termites to hollow a tree out. Harvesting has to be timed so that the wall thickness of the instrument is not too thin or not too thick. The varying length of the wood that is sawed off and its thickness and shape will determine which key the instrument will be in.
Shorter lengths yield higher pitches where as longer lengths yield lower pitches.
The key of C is one of the easiest keys to learn how to play on the didgeridoo. To hear the different keys click here . Bark is usually stripped from the outside and the termites removed. A rim of beeswax can then be applied to reduce the diameter of a large opening down to more playable sized aperture. About an inch and a quarter, similar to a tuba sized mouthpiece.