Yamaha Clavinova PF P-100 Owner's Manual - page 34
MIDI KEYBOARD CONTROL FUNCTIONS
What is MIDI?
MIDI is an acronym for Musical Instrument Digital Interface. This is the name of an international standard which was
instituted during the 1980s to provide for the communication of data between electronic musical instruments.
The MIDI standard allows instruments such as synthesizers, tone generators, and drum machines — not to mention
electronic pianos such as the P-100 — to communicate with each other, and to be controlled by sequencers or
computers.
MIDI is a rather involved standard, and we will not attempt to explain all of its provisions in this short manual. You
will find it easier to put MIDI to work, however, if you understand a few of the basic concepts behind the standard.
Two of the most important concepts in MIDI are those of channels and messages.
Channels
The MIDI standard provides 16 different channels for
the transmission of data between musical instruments.
All MIDI keyboards are capable of transmitting data
on at least one of these channels. Sequencers and
MIDI-equipped computers, by contrast, generally
transmit data on several channels at once, each chan-
nel being assigned to a different part of an ensemble
performance.
It is the task of tone generators to receive MIDI data
from keyboards, sequencers, or computers and
produce sounds in response. Some tone generators,
known as multitimbral tone generators, can play
different sounds in response to data received on more
than one channel. If this makes you think of the P-
100’s Dual and Split modes, then you’re right on
target: the P-100 actually consists of a MIDI keyboard
and a multitimbral tone generator capable of
producing two timbres simultaneously. We’ll take a
detailed look at how these hardware elements work
together in the next section.
Messages
All of the data which is transmitted between MIDI
devices takes the form of MIDI messages of one sort
or another. The messages most closely associated with
the actual performance of music are called channel
voice messages. These include note on and note off
messages, which tell a tone generator which notes to
play, and when to start and stop playing them: control
change, pitch bend, and aftertouch or key pressure
messages, which indicate how a keyboard’s control
functions are being operated: and program change
messages. which tell a tone generator to switch to
another sound or set of sounds.
Channel voice messages must be transmitted on a
channel which will be received by the tone generator
for which they are intended. They are thus different
from system messages, which are transmitted on all
channels and received by all of the devices in a MIDI
system.
System messages, too, come in a number of varieties.
There are system realtime messages, which are used
to start, stop, and synchronize the sequencing devices
in a MIDI system. Another variety, system exclusive
messages, allows for the transmission of data specific
to individual devices. This data can be either indi-
vidual parameter settings, which are transmitted as
parameter change messages, or large blocks of
settings, which are usually referred to as bulk dumps.
There are several other kinds of MIDI messages that
we will not go into here. When using the P-100’s
MIDI functions, you will be concerned mainly with
only two types of messages: channel voice messages
and system exclusive messages. To learn what other
sorts of messages the P-100 supports, and how their
corresponding functions are implemented, you can
refer to the MIDI Data Format and MIDI
Implementation Chart sections at the back of this
manual.
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