A MIDI controller is a device that allows musicians and producers to create and manipulate music using MIDI (Musical Instrument Digital Interface) signals. These controllers can come in various forms, such as keyboards, drum pads, or even specialized devices for controlling software instruments. They do not produce sound on their own but send data to a computer or synthesizer to trigger sounds. MIDI controllers are widely used in music production, live performances, and studio settings. They enable users to control parameters like pitch, volume, and effects in real-time, making it easier to compose and arrange music. Popular brands include Akai, Novation, and Korg.