MIDI
Part XIII | MIDI |
MIDI channels
Many different kinds of performance data are sent using just one MIDI cable. This is possible because MIDI signals are sent and received through 16 different “basic channels” (numbered 1 to 16). In order for the exchange of data to take place, the channels on the transmission side must match the channels on the receiving side. This characteristic also makes it possible to link multiple sound generators and to control each by matching specific channels.
The following kinds of data can be transmitted/received.
■NOTE data
This is the most basic kind of MIDI data which is exchanged, and is used to specify which keys are played and how hard they are played.
NOTE NUMBER: Number specifying which key is played.
NOTE ON: Specifies that a key is played.
NOTE OFF: Specifies that a key is released.
VELOCITY: Specifies how hard a key is struck.
•MIDI notes are assigned numbers from 0 to 127, with middle C (C3) as 60. Note pitches are in semitone increments, with the higher numbers assigned to the higher pitches.
■PROGRAM CHANGE
This is sound change data. When a different sound is selected on the transmitting instrument, the sound on the receiving instrument also changes.
■CONTROL CHANGE
These are volume, sustain, effect, etc. data used to enhance performance expression. Each func- tion is distinguished by its control number, and the function which can be changed by the control differs depending on the instrument.
■EXCLUSIVE data
This is data that is specific to this instrument, and data for the GENERAL MIDI LEVEL 2 mode set- ting.
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