1911 Encyclopædia Britannica/Pibroch

PIBROCH, a form of music as played by the bagpipe. The word is derived from the Gaelic piobaireachd, the art of the bagpiper. This special form of bagpipe music, consisting of a series of variations founded on a theme, was called the urlar. These variations are generally of a martial or warlike character and include dirges and marches (see Bagpipe).