Similarly, a drone is the name of the part of a musical instrument intended to produce such a sustained pitch, generally without the ongoing attention of the player. Different melodic Indian instruments (e.g. Sitar, Sarod, Sarangi, Rudra Veena) contain a drone. For example the Sitar features three or four resonating drone strings and Indian notes (sargam) are practiced to a drone. Bagpipes (like the Great Highland Bagpipe and the Uilleann pipes) feature a number of drone pipes, giving the instruments their characteristic sounds. A hurdy-gurdy has one or more drone strings. The fifth string on a five-string banjo is a drone string with a separate tuning peg that places the end of the string five frets down the neck of the instrument; this string is usually tuned to the same note as that which the first string produces when played at the fifth fret, and the drone string is seldom fretted. The bass strings of the Slovenian drone zither also freely resonate as a drone.
However, drones are less often used in common practice classical music because the longer and more central a drone the less functional it is and because equal temperament causes slight mistunings which become more apparent over a drone, especially when also sustained. On the other hand, drones may be purposely dissonant, as often found in the music of Phill Niblock. The best known drone piece in the concert repertory is the Prelude to Wagner's Rheingold (1854) wherein the bass instruments sustain an Eb throughout the entire movement (Erickson 1975, p.94). Later drone pieces include Loren Rush's Hard Music (1970), Folke Rabe's Was?? (1968), and Robert Erickson's Down at Piraeus.
Contemporary classical musicians who make prominent use of drones, often with just or other non-equal tempered tunings, include La Monte Young and many of his students, David First, the band Coil, the early experimental compilations of John Cale (Sun Blindness Music, Dream Interpretation (Album), and Stainless Gamelan), Pauline Oliveros and Stuart Dempster, Alvin Lucier (Music On A Long Thin Wire), Ellen Fullman, and Arnold Dreyblatt. The music of Italian composer Giacinto Scelsi is essentially drone-based. Shorter drones or the general concept of a continuous element are often used by many other composers.
A drone differs from a pedal tone or point in degree or quality. A pedal point may be a form of nonchord tone and thus required to resolve unlike a drone, or a pedal point may simply be considered a shorter drone, a drone being a longer pedal point.
The term comes from the French bourdon, a staff; or a pipe made in the form of a staff, imitating the gross murmurs of bees or drones.
This is what was anciently called proslambanomenos.