Bass pedals are an electronic musical instrument with a foot-operated pedal keyboard with a range of one or more octaves. The earliest bass pedals from the 1970s consisted of a pedalboard and analog synthesizer tone generation circuitry packaged together as a unit. The bass pedals are plugged into a bass amplifier or PA system so that their sound can be heard. Since the 1990s, bass pedals are usually MIDI controllers, which have to be connected to a MIDI-compatible computer, electronic synthesizer keyboard, or synth module to produce musical tones. Some 2010s-era bass pedals have both an onboard synth module and a MIDI output.
Bass pedals serve the same function as the pedalboard on a pipe organ or an electric organ, and usually produce sounds in the bass range, which, in organ terminology is the 16′ stop. Some bass pedals have an 8′ stop (an octave higher) which can be used by itself or combined with the 16' stop. Bass pedals are used by keyboard players as an adjunct to their full-range manual keyboards (the keyboards played with the hands), by performers of other instruments (e.g., electric bass or electric guitar), or by themselves. Bass pedal units usually have a smaller range (13 notes) than a church pipe organ's pedal keyboard (32 notes for an American Guild of Organists standard pedalboard). Bass pedals with larger ranges are less common, but do exist, such as 17 notes (C to E), 20 notes (C to G), and 25 notes (C to C two octaves higher). As well, bass pedals usually have shorter pedals than those on a church pipe organ's pedalboard.