The History of MIDI

MIDI stands for Musical Instrument Digital Interface. It is a protocol that enables various electronic musical instruments, apparatus and computers to communicate with each other.

MIDI is a completely different animal from digital audio. The latter originates from actual sound waves which were then mathematically reduced into 1's and 0's through a process known as sampling. The machine that does the sampling are generally called analog-to-digital or digital-to-analog converters. These converters are standard components of computer sound cards. With the audio waves turned into audio data, they can now be copied, transferred and reproduced into any machine capable of reading such data - a computer with a media player installed for example. MIDI, on the other hand, does not deal with audio signals at all. A MIDI device transmits what are called event messages. These messages contain codes that define specific musical properties such as pitch, tempo, attack, delay, vibrato, volume, etc. When a MIDI-capable sound generating device such as a keyboard synthesizer reads these messages, it will produce the sound according to what the message specifies.

MIDI technology was first proposed as an industry standard in 1981 by Dave Smith, an audio engineer and synthesizer designer from Sequential Circuits, Inc. The objective was to solve the growing incompatibility of electronic musical devices, specifically synthesizers, as each manufacturer was developing its own protocols. By August 1983, the MIDI Specification 1.0 was published and a new era in electronic musical instrument design began. Two organizations were established that developed and standardized MIDI and they continue to maintain the standards today. One is the MIDI Manufacturers Association (MMA) based in Los Angeles, California and the other is the MIDI Committee of the Association of Musical Electronic Industry (AMEI) based in Tokyo, Japan.

Before the inception of MIDI, keyboardists had no recourse but to set up and surround themselves with several keyboard synthesizers in order to access the sound bank and take advantage of the features of each machine. With MIDI as a standard, they can now control and access several devices from a single keyboard. A new type of device was soon developed called sequencers. These enabled musicians to control MIDI information and thus create compositions or arrangements. They started out as either separate hardware modules or were integrated into the keyboard synthesizers. It didn't take long for the technology to migrate into other areas of the electronic industry such as computers. Now sequencers are more known as software to be installed into PCs to enable computer-based music production. It is now also common for computer operating systems and soundcards to include MIDI software/hardware synthesizers capable of reading MIDI information and reproduce the corresponding sound.

The most common version of the MIDI standard is called General MIDI (GM). This was released in 1991 by both the MMA and the AMEI. It provides more specific requirements than the original MIDI Specification 1.0. For an electronic musical device to be GM-compatible it has to be able to respond to note velocity (how hard the note is struck on the keyboard), allow 24-note polyphony (24 notes played at the same time) and allow all 16 channels to be active simultaneously.