What Can You Connect to a MIDI Port?

Keyboards

MIDI keyboards are the most common type of MIDI device. A MIDI keyboard includes, at the very least, a piano-style keyboard, which is often scaled down from 88 keys to 25, 32 or 49. Most MIDI keyboards include a pitch wheel or lever, which allows the performer to bend the pitch of a note while playing. More advanced models also have a modulation wheel, which you can link up to any of the various parameters in a software synthesizer. Nearly all MIDI keyboards incorporate a series of knobs and sliders with which you can control audio software on the computer.

A MIDI drum machine is designed to control a virtual drum machine via the MIDI port. The most complex MIDI drum machines look and feel like a real drum kit; the drummer plays this type of instrument using actual drumsticks. Simpler MIDI drum machines consist of a series of touch-sensitive pads embedded into the device; the performer plays this type of drum machine by tapping the pads with his fingers. Although these devices are designed for virtual drumming, many musicians also use them to trigger other audio samples in a digital audio workstation.

Other MIDI instruments allow the performer to control audio software using a physical interface with which she is familiar. MIDI guitars, for example, allow the musician to play a synthesizer by "strumming" a series of buttons. Breath-controlled MIDI devices emulate wind and brass instruments like flutes, saxophones and clarinets. The harder the player blows into one of these instruments, the higher the MIDI velocity and the louder the resulting sound. MIDI guitar pedals allow guitarists to control virtual audio effects using a MIDI connection.

Some MIDI devices don't resemble traditional instruments at all; rather, they consist of a series of knobs, trigger pads, sliders and wheels, similar to an audio mixer. These MIDI devices are designed more for audio production than for live performance; however, they can be very useful when DJing on a computer. DJs can, for example, link the knobs on a controller to the audio effects they plan to use in their sets, then use the faders on the MIDI controller to bring tracks in and out of the mix.