drone

In music, a continuous accompanying note usually played in the bass. Its main feature is that it is sustained or persistently repeated throughout a piece or part of a piece of music. It is found in many classical and folk traditions, is common in the vocal music of the Russian, Greek, and Bulgarian Orthodox Churches, and is produced by many folk music instruments, including the Indian vina, bagpipes, and hurdy-gurdy. Drone effects in written music include the organ pedal point and the musette dance form.

Drone is also the name given to the three lower pipes of the bagpipes, which produce a fixed chord above which the melody is played on the chanter. It is also a bowed instrument with a single string stretched on a stick over a bladder, sometimes called a bumbass.

Among examples of drone in the concert repertoire are Wagner's overture to Das Rheingold/The Rhinegold (1853-54) and the mystery chord of Schoenberg's third orchestral piece ‘Farben’/‘Chord Colours’ from the Five Pieces for Orchestra (1909).