DRONE, in music  (corresponding to Fr. bourdon; Ger. Summer, Stimmer, Hummel; Ital. bordone), the bass pipe or pipes of the bagpipe, having no lateral holes and therefore giving out the same note without intermission as long as there is wind in the bag, thus forming a continuous pedal, or drone bass. The drone consists of a jointed pipe having a cylindrical bore and usually terminating in a bell. During the middle ages bagpipes are represented in miniatures with conical drones,  and M. Praetorius  gives a drawing of a bagpipe, which he calls Grosser Bock, having two drones ending in a curved ram's horn. The drone pipe has, instead of a mouthpiece, a socket fitted with a reed, and inserted into a stock or short pipe immovably fixed in an aperture of the bag. The reed is of the kind known as beating reed or squeaker, prepared by making a cut in the direction of the circumference of the pipe and splitting back the reed from the cut towards a joint or knot, thus leaving a flap or tongue which vibrates or beats, alternately opening and closing the aperture. The sound is produced by the stream of air forced from the bag by the pressure of the performer's arm causing the reed tongue to vibrate over the aperture, thus setting the whole column of air in vibration. Like all cylindrical pipes with reed mouthpiece, the drone pipe has the acoustic properties of the closed pipe and produces a note of the same pitch as that of an open pipe twice its length. The conical drones mentioned above would, therefore, speak an octave higher than a cylindrical drone of the same length. The drones are tuned by means of sliding tubes at the joints.
The drones of the old French cornemuse played in concert with the hautbois de Poitou (see Bagpipe), and differing from the shepherd's cornemuse or chalémie, formed an exception to this method of construction, being furnished with double reeds like that of the oboe. The drones of the musette and of the union pipes of Ireland are also constructed on an altogether different plan. Instead of having long cumbersome pipes, pointing over the shoulder, the musette drones consist of a short barrel containing lengths of tubing necessary for four or five drones, reduced to the most compact form and resembling the rackett (q.v.). The narrow bores are pierced longitudinally through the thickness of the barrel in parallel channels communicating with each other in twos or threes, and so arranged as to provide the requisite length for each drone. The reeds are double reeds all set in the wooden stock within the bag. By means of regulating slides (called in English regulators and in French layettes), which may be pushed up and down in longitudinal grooves round the circumference of the barrel, the length of each drone tube can be so regulated that a simple harmonic bass consisting of the common chord is obtainable. In the union pipes the drones are separate pipes having keys played by the elbow, which correspond to the sliders in the musette drone and produce the same kind of harmonic bass. The modern Egyptian arghool consists of a kind of clarinet with a drone attached to it by means of waxed thread; in this case the beating reed of the drone is set in vibration directly by the breath of the performer, who takes both mouthpieces into his mouth, without the medium of a wind reservoir. Mersenne gave very clear descriptions of the construction of cornemuse and musette, with clear illustrations of the reeds and stock.  There are allusions in the Greek classics which point to the existence of a pipe with a drone, either of the arghool or the bagpipe type. 
 For the "drone," the male of the honey bee, see Bee. The musical sense, both for the noise made and for the instrument, comes from the buzzing of the bee.
 Syntagma musicum. Theatrum instrumentorum, pl. xi. No. 6.
 L'Harmonie universelle (Paris, 1636-1637), t. ii. bk. 5, pp. 282-287 and p. 305.
 Plato, Crito, 54; Aristophanes, Acharnians, 865, where some musicians are in derision dubbed "bumblebee pipers." See Bagpipe; also Kathleen Schlesinger, "Researches into the Origin of the Organs of the Ancients," Intern. mus. Ges. vol. ii. (1901), Sammelband ii. pp. 188-202.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)