A pedal point is a single sustained note over which chords move and change, at times even dissonating with it. The name comes from the organ, where a bass note can easily be held by the pedal for as long as desired.
Most often a pedal point is built on the tonic (creating a sense of an immovable foundation, of repose) or on the dominant (building tension before a powerful resolution to the tonic — a favourite device before a climax). A sustained bass lends music depth and monumentality. The pedal point was masterfully used from J.S. Bach to the Romantics and 20th-century composers; kindred to it is the drone — the unchanging humming tone of folk music, including the Ukrainian kolisna lira and the bagpipe.
