MIDI controller

A MIDI controller is any hardware or software that generates and transmits Musical Instrument Digital Interface (MIDI) data to electronic or digital MIDI-enabled devices, typically to trigger sounds and control parameters of an electronic music performance. The most commonly used MIDI controller is the electronic musical keyboard MIDI controller, which has keys that can be pressed. When the keys are pressed, the MIDI controller sends MIDI data about the pitch of the note, the velocity and duration, which can be used to trigger sounds from a MIDI-compatible sound module or synthesizer.

Other common MIDI controllers are wind controllers, which a musician blows into and presses keys to transmit MIDI data, and electronic drums, which are typically struck with sticks to create MIDI data. MIDI controllers do not usually create or produce musical sounds by themselves. MIDI controllers typically have some type of interface which the performer presses, strikes, blows or touches. This action generates MIDI data (e.g., on what note was played, for how long, and with which rhythm), which can then be transmitted to a MIDI-compatible sound module or synth using a MIDI cable. The sound module or synth in turn produces a sound which is amplified through a loudspeaker.

There are many other types of MIDI controllers. A slider assigned to open and close a low-pass filter on a synthesizer may be assigned to controller 18, for example. Changes in the position of the slider are transmitted along with "18" so that they are distinguished from changes in the value of other controllers. The MIDI controller can be populated with any number of sliders, knobs, buttons, pedals and other sensors, and may or may not include a piano keyboard. While the most common use of MIDI controllers is to trigger musical sounds and play musical instruments, MIDI controllers are also used to control other MIDI-compatible devices, such as stage lights, digital audio mixers and complex guitar effects units.

The following are classes of MIDI (Musical Instrument Digital Interface) controller:

MIDI was designed with keyboards in mind, and any controller that is not a keyboard is considered an "alternative" controller. This was seen as a limitation by composers who were not interested in keyboard-based music, but the standard proved flexible, and MIDI compatibility was introduced to other types of controllers, including guitars, wind instruments and drum machines.

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