MIDI messages are the core of MIDI communication. These messages serve as the language through which your musical intentions are translated into action by MIDI-capable devices. Let's delve into a few examples:
- Note-On and Note-Off Messages: These messages inform MIDI devices when a musical note should start (Note-On) and stop (Note-Off). When you press a key on a MIDI keyboard, it generates a "Note-On" message. This message includes information about which note to play and with what force (velocity). The receiving device, such as a synthesizer, responds by producing the specified musical sound at the designated pitch and velocity. This is how MIDI allows you to play melodies and chords.
- Control Change Messages: Control change messages provide a way to adjust parameters like volume, modulation, and filter cutoff. Musicians use these messages to shape the sound of their instruments.
- Program Change Messages: MIDI allows you to switch between different instrument sounds (known as "patches" or "presets") seamlessly. A "Program Change" message tells the receiving device to switch to a specific instrument or sound preset, making it possible to explore a wide range of sonic possibilities within a single instrument.
- Pitch Bend Messages: Pitch bend messages control the pitch deviation of a note, mimicking techniques like vibrato on instruments such as synthesizers and keyboards.
- Aftertouch Messages: Aftertouch messages convey the pressure applied to a key after it's initially pressed, enabling expressive control over various aspects of a sound, like vibrato or filter modulation.
Now that we've explored the fundamental language of MIDI, let's delve into the practical tools used for sending these commands.