Chorus effect in the context of "Amplified music"

An instrument amplifier is an electronic amplifier that converts the often barely audible or purely electronic signal of a musical instrument into a larger electronic signal to feed to a loudspeaker. An instrument amplifier is used with musical instruments such as an electric guitar, an electric bass, electric organ, electric piano, synthesizers and drum machine to convert the signal from the pickup (with guitars and other string instruments and some keyboards) or other sound source (e.g, a synthesizer's signal) into an electronic signal that has enough power, produced by a power amplifier, to drive one or more loudspeaker that can be heard by the performers and audience.

Combination (combo) amplifiers include a preamplifier, a power amplifier, tone controls, and one or more speakers in a cabinet, a housing or box usually made of wood. Instrument amplifiers for some instruments are also available without an internal speaker; these amplifiers, called heads, must plug into one or more separate speaker cabinets. Instrument amplifiers also have features that let the performer modify the signal's tone, such as changing the equalization (adjusting bass and treble tone) or adding electronic effects such as intentional distortion or overdrive, reverb or chorus effect.

The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided by a rotating system of horns in front of the treble driver. It is most commonly associated with the Hammond organ, though it was later used for the electric guitar and other instruments. A typical Leslie speaker contains an amplifier, a treble horn and a bass speaker—though specific components depend upon the model. A musician controls the Leslie speaker by either an external switch or pedal that alternates between a low and high speed setting, known as "chorale" and "tremolo".

The speaker is named after its inventor, Donald Leslie, who began working in the late 1930s to get a speaker for a Hammond organ that better emulated a pipe or theatre organ, and discovered that baffles rotating along the axis of the speaker cone gave the best sound effect. Hammond was not interested in marketing or selling the speakers, so Leslie sold them himself as an add-on, targeting other organs as well as Hammond. Leslie made the first speaker in 1941. The sound of the organ being played through his speaker received national radio exposure across the US, and it became a commercial and critical success. It soon became an essential tool for most jazz organists. In 1965, Leslie sold his business to CBS who, in 1980, sold it to Hammond. Suzuki Musical Instrument Corporation subsequently acquired the Hammond and Leslie brands.

The Roland Space Echo is a line of tape delay units introduced by Roland Corporation in 1974.

Whereas prior tape delay effects used tape reels, the Space Echo uses a free-running tape transport system. This reduces tape wear, noise, and wow and flutter, and made the units more reliable and easy to transport. Some units also feature spring reverb and chorus effects.