Taken from the Roland SCC-1 Owner's Manual , page 23-24.

MIDI stands for Musical Instrumental Digital Interface, a world-wide standard for exchanging performance data among computers and electronic musical instruments. An instrument conforming to the MIDI standard, no matter what kind or who made it, can send and receive performance data. This MIDI data is not music itself, but rather a way of handling a variety of digitally-encoded messages telling the instrument what to do.

Midi data exchange is not that difficult to understand.

MIDI Connections

MIDI data exchange is achieved through three connectors. MIDI cables are used to connect these connectors in whatever arrangement you need for a particular job.

MIDI IN : MIDI data is received from other devices.

MIDI OUT : Data is sent to other devices.

MIDI THRU : The data sent to MIDI IN is sent back out, unchanged.

MIDI Channels

Data for a number of different MIDI devices can be sent over the same MIDI cable. This is the result of the MIDI Channel concept.

A MIDI Channel is a lot like a TV Channel. As you switch channels, you see completely different programs; but this information is only received when the channel on your TV is set to the same channel that the TV station is broadcasting on.

MIDI has channels numbered 1-16, and MIDI data on any one channel is sent to all instruments set to receive on that same channel. For example, a MIDI cable connects a MIDI keyboard's MIDI OUT connector to sound module A's MIDI IN connector. Another MIDI cable connects sound module A's MIDI THRU connector to sound module B's MIDI IN. The keyboard is set to trasmit at channel 1, sound module A is set to receive at channel 2, and sound module B is to receive from channel 1. Because the keyboard is transmitting at channel 1, and only sound module B is receiving at channel 1, only sound module B will play.

Back to the MIDI Page .