The earliest brass instruments were straight or curved open horns made from wood, bone and animal horns. These usually consisted of a mouthpiece affixed to a cylindrical tube that produced only one note. They existed in the earliest cultures of Egypt, India, New Guinea, Brazil and Australia.
The didgeridoo is played with continuously vibrating lips to produce a continuous drone while using a special breathing technique called circular breathing.
The didgeridoo was developed by Aboriginal peoples of northern Australia at least 1,500 years ago, and is now in use around the world, though still most strongly associated with Indigenous Australian music.