MIDI is an acronym that stands for Musical Instrument Digital Interface. It’s a way to connect devices that make and control sound — such as synthesizers, samplers, and computers — so that they can communicate with each other, using MIDI messages. This lets one keyboard trigger sounds on another synthesizer, and it makes it possible to record music in a form that allows for easy note editing, flexible orchestration, and song arrangement. Virtual instruments — computer programs that simulate hardware synthesizers and samplers — also communicate with computer sequencing software running on the same computer using MIDI messages.
This web page introduces you to the basics of MIDI. The interactive application you can download from the syllabus helps you to understand some specifics of MIDI messages.