MIDI (Musical Instrument Digital Interface) is a language used to represent and communicate musical information. It is read, recorded and played by digital devices such as computers and electronic instruments. Since its invention in the 1980s, MIDI technology has introduced a whole new range of artistic options and musical styles.
MIDI devices do not record sounds, but, rather, the following information about a musical event:
- Pitch: What notes on the scale are being played?
- Timing: When are these notes being played?
- Velocity: How forcefully is each note being played?
- Control signals: What panning, vibrato and volume settings are being used?
After MIDI information is created, a sound generator such as a computer or synthesizer can read it and play listenable songs.
MIDI information is recorded on and read by:
MIDI instruments: These look like regular instruments, such as guitars and pianos, but have built-in electronic interfaces to record and play back MIDI information.
Computers: A DAW (digital audio workstation) installed on a computer can record and play back MIDI information.
How to Use MIDI:
One of the easiest and most efficient ways to use MIDI is to purchase any classic DAW, such as ProTools, and a MIDI instrument, such as a keyboard. A user can attach the MIDI keyboard to the computer with a USB cord. Then, within the DAW, (s)he can create and record a MIDI sequence by playing the MIDI instrument or by drawing notes with a mouse. The DAW typically has built-in software synthesizers that can read and play this information. The user can also purchase third-party software synthesizers for the DAW, or the computer can play the MIDI information through hardware synthesizers.
Benefits of MIDI:
Errors can easily be corrected. In the old days of studio recording, a musician may have had to play the same part 100s of times to get it exactly right. Now, if (s)he plays the part once and makes an error, (s)he or the studio engineer can fix the error with one mouse click.
Complex musical arrangements can be made rapidly and efficiently. The same MIDI sequence can be played by any instrument anywhere at any time, without additional recording. Repetitive parts of a song only have to be recorded once, even if the instrumentation is different. One part can be played through many instruments and layered in a DAW to form a complex arrangement.
MIDI information can automatically be translated into sheet music by DAWs. This is especially useful for composers who can’t read music but write parts for classically trained musicians.
Timing can be altered while maintaining other elements of the song, such as note length and instrument timbre. If a composer wants to listen to a song with different grooves (swing, reggae, etc.), these groove templates can be applied to an entire song in one click.
Melodic themes and alterations can easily be created. To develop a song, a composer may want to create slight variations to a musical idea throughout the piece. To do this, (s)he can play just one line of melody on a MIDI instrument. Then, rather than playing all of the notes again with new variations, (s)he can simply duplicate the sequence, edit one or two notes, and play back the revised sequence to see if it suits the song.
Transposition is not only easy, but addresses sound quality issues. With digital technology, it is possible to transpose (change the pitch of) audio files without using MIDI. However, at certain pitches, a transposed instrument sample might sound odd or unnatural. To address this issue, audio software manufacturers record samples of real instruments at all different pitches. If a composer wants to transpose a piece of music, then, (s)he can transpose the MIDI notes rather than the audio file. The computer can then play real instrument samples in the new key, rather than distorted versions of the original samples.
Things to be aware of when using MIDI:
Music often sounds best with an organic, natural feel. Fixing the timing using the quantize feature or drawing notes in a DAW may make the music sound too stilted and mechanical.
Since MIDI information is not actual audio, it is important that an artist has access to a sound source, such as a virtual instrument, to hear the song.
Programming MIDI is not a substitute for musicianship and practice!