What is the buzzing sound I hear?
The Great Highland Bagpipe has four reeds which sound simultaneously and continuously. Three of the reeds are drone reeds, a bass and two tenors and emit a drone sound in unison. Presumably the pipes belong to a competitive piper and are well tuned, in which case the listener will be entertained with a pleasing buzzing sound in the background. The buzzing sound is the interaction of the second, third, and fourth harmonics of the fundamental of each individual drone.
