Basic MIDI terms dictionary

MIDI – it is the interface for music equipment usage. It enables transmission of commands, messages and other occurrences between connected devices. Practically two kinds of commands are used in guitar’s controlling systems: Program Change (change the program) and Control Change (change the control parameter). Interface sends the commands in one direction from MIDI OUT to MIDI IN. Thanks to the transoptors it doesn’t cause the ground loops. Most of 19” rack effects features MIDI IN input that enables to control them. MIDI foot guitar controllers (e.g. GLAB GSC-2/3) feature MIDI OUT output and can be programmed to send the Prog. Change and Contr. Change commands. Thanks to addressing via MIDI CHANNELs one controller can control number of devices (up to 16).

MIDI CHANNEL – No. of the channel (from 1 to 16) on which is sent given command. Receiving device can receive the commands on every channel (OMNI mode) or on the previously chosen channel. In some devices the receiving channel (MIDI IN CHANNEL) is set independently from sending channels (MIDI OUT CHANNEL).

Program Change command (PrCh) – MIDI interface command transmitting the No. of program (preset) to recall (from 1 to 128). The example of using Prog. Change command is recalling the preset/sound in the multi-effect controlled via MIDI

Control Change command (CC or CtrlCh) – MIDI interface command transmitting the No. of controller (from 0 to 127) and the controller’s value (from 0 to 127). Receiving devices treat the controller’s number as the chosen parameter and they treat value as setting/adjustment of the parameter. The value of the controller can work in continuous parameter mode from 0 to 127 (e. g. volume adjustment), in limited range (e. g. delay time in delay type effect from 5 to 127 x 10 ms) or even control ON/OFF type parameter (e. g. from 0 to 63 – effect off and 64 to 127 – effect on)

MIDI THRU – it is MIDI transmission output socket with a copy of the signal which comes to device’s MIDI IN input. Thanks to that one talking device can control number of MIDI devices. In some devices it is possible to set the MIDI OUT output on MIDI THRU software mode.