The SMF file format allows users to exchange MIDI data regardless of the computer operating system and has provided a basis for an efficient internet-wide distribution of music data, including numerous websites devoted to the sale and exchange of music. In the following, we denote SMF files simply as MIDI files The original MIDI standard was later augmented to include the Standard MIDI File (SMF) specification, which describes how MIDI data should be stored on a computer. It is an important fact that MIDI does not represent musical sound directly, but only represents performance information encoding the instructions about how an instrument has been played or how music is to be produced. These MIDI messages may be automatically generated by some other electronic instrument or may be provided by a computer. Instead of physically pushing and releasing the piano key, the musician may also trigger the instrument to produce the same sound by transmitting suitable MIDI messages, which encode the note-on, the velocity, the note-off, and other information. The intensity of the sound is controlled by the velocity of the keystroke.

As an example, let us consider a digital piano, where a musician pushes down a key of the piano keyboard to start a sound. MIDI allows a musician to remotely and automatically control an electronic instrument or a digital synthesizer in real time.

It was the advent of MIDI in 1981–1983 that caused a rapid growth of the electronic musical instrument market. MIDI (Musical Instrument Digital Interface) was originally developed as an industry standard to get digital electronic musical instruments from different manufacturers to work and play together.

Midi note to pd number chart