Since the 1990s, most electronic pedalboards have been MIDI controllers, which do not perform any tone generation themselves.

Thunder is a pure MIDI controller, with no internal sound generator of its own.

The most common MIDI controllers encountered are various sizes of "piano" keyboard.

In the late 1980s it was common to use a MIDI controller to control more than one keyboard from a single device.

However, different products used different sounds attached to their MIDI controllers.

The term "MIDI controller" is used in two different ways.

The following are types of MIDI controller, according to definition 1 above:

Keyboards are by far the most common type of MIDI controller.

The keyboard isn't just a cute peripheral, it's a working MIDI controller.

Actually people have already been using the iphone as a MIDI controller for awhile.