Russell Feingold, a transformational coach, plays the Didgeridoo during the Eco Gift Expo at Santa Monica Civic on Sunday, December 16, 2007. The didgeridoo is a wind instrument of the Indigenous Australians of northern Australia. It is sometimes described as a natural wooden trumpet or "drone pipe". Musicologists classify it as an aerophone. A didgeridoo is usually cylindrical or conical in shape and can measure anywhere from 1,2 and 3 metres in length with most instruments measuring around 1.2 metres. Generally, the longer the instrument, the lower the pitch or key of the instrument. Keys from D to F♯ are the preferred pitch of traditional Aboriginal players.