What is MIDI?
MIDI stands for Musical Instrument Digital Interface. It is a language used for exchanging information between electronic musical instruments, sound modules and computers. Musical instruments include digital pianos, synthesizers and other keyboards. There are also guitars and basses that are MIDI capable. Computers use MIDI information to play internal sounds in the computer’s sound card or in “soft synth” programs. A computer with a MIDI sequencing program, such as Cakewalk, can send MIDI information to an instrument or sound module.
Information is transmitted between instruments, sound modules and computers by a cable, either a MIDI cable or a USB cable. The MIDI information determines the instrument sound to be played, the pitch, length, volume, velocity and much more information. The information transmitted is not the sound generated.
Let’s say you have a MIDI keyboards. When you play a note using a piano sound on one keyboard, MIDI information is produced. The pitch of the note, the volume of the note, how hard you press on the key, whether or not the sustain pedal is depressed, and so on. This MIDI language is send to the internal sound module and a piano note 9or any other instrument sound you select) played by a piano is produced through your speakers or headphones.
If you connect your MIDI keyboard to another MIDI keyboard using the appropriate cable and input/output, then the MIDI information created by pressing the keyboard is also sent to the second MIDI keyboard. However, the second MIDI keyboard may be set-up so that an orchestra sound is produced, rather than a piano sound like the first MIDI keyboard. All the volume, pitch, length, and sustain pedal information is the same. The sounds are now “layered.”
Taking it one step further, you can connect a computer to the two MIDI keyboards. Using a sequencer program, you can ‘record’ the MIDI information you transmit and save it for future editing. You simply play a keyboard while the sequencer software records the MIDI information. The information might be displayed on the computer screen as musical notation, or as a piano roll, or as a list of events. By editing the recorded MIDI information, you can correct mistakes, transpose, change tempo, change the instrument sounds and add more musical parts, all of which can be “played back” by sending the MIDI information to your MIDI keyboard(s).