Yamaha CVP-409 - Manual (Page 197)

Using
Your Instrument with Other Devices
CVP-409/407 Owner’s Manual 197
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In the case of digital instruments, the audio signals are sent
through output jacks (such as [AUX OUT]) on the instrument.
The “controller” and “tone generator” in the illustration
above are equivalent to the piano in our acoustic exam-
ple. Here, the player’s performance on the keyboard is
captured as MIDI song data (see illustration below). In
order to record the audio performance on an acoustic
piano, special recording equipment is needed. How-
ever, since the instrument features a built-in sequencer
that lets you record performance data, this recording
equipment is unnecessary. Instead, your digital instru-
ment—the Clavinova—allows you to both record and
play back the data.
However, we also need a sound source to produce the
audio, which eventually comes from your speakers. The
tone generator of the instrument fills this function. The
recorded performance is reproduced by the sequencer,
playing back the song data, using a tone generator
capable of accurately producing various instrument
sounds—including that of a piano. Looked at in another
way, the relation of the sequencer and the tone genera-
tor is similar to that of the pianist and the piano—one
plays the other. Since digital instruments handle play-
back data and the actual sounds independently, we can
hear our piano performance played by another instru-
ment, such as guitar or violin.
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Even though it is a single musical instrument, the instrument can
be thought of as containing several electronic components: a con-
troller, a tone generator, and a sequencer.
Finally, we’ll take a look at the actual data that gets
recorded and that serves as the basis for playing the
sounds. For example, let’s say you play a “C” quarter
note using the grand piano sound on the instrument’s
keyboard. Unlike an acoustic instrument that puts out a
resonated note, the electronic instrument puts out infor-
mation from the keyboard such as “with what voice,”
“with which key,” “about how strong,” “when was it
pressed” and “when was it released.” Then each piece
of information is changed into a number value and sent
to the tone generator. Using these numbers as a basis
for sound generation, the tone generator plays the
stored sampled note.
Example Keyboard Data
Panel operations on the instrument, such as playing the
keyboard and selecting voices, are processed and
stored as MIDI data. The auto accompaniment Styles
and Songs also consist of MIDI data.
MIDI is an acronym that stands for Musical Instrument
Digital Interface, which allows electronic musical
instruments to communicate with each other, by send-
ing and receiving compatible Note, Control Change,
Program Change and various other types of MIDI data,
or messages.
The instrument can control a MIDI device by transmit-
ting note related data and various types of controller
data. The instrument can be controlled by incoming
MIDI messages which automatically determine the tone
generator mode, select MIDI channels, voices and
effects, change parameter values and of course play the
voices specified for the various parts.
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MIDI data has the following advantages over audio data:
• The amount of data is much less.
• The data can be effectively and easily edited, even to the point
of changing voices and transforming the data.
MIDI messages can be divided into two groups: Chan-
nel messages and System messages.
Channel Messages
The instrument is an electronic instrument that can han-
dle 16 MIDI channels (or reception of 32 channels for
MIDI data reception when using the [USB] terminal).
This is usually expressed as “it can play 16 instruments
at the same time.” Channel messages transmit informa-
tion such as Note ON/OFF, Program Change, for each
of the 16 channels.
Sequencer
Tone Generator
Recording and play back the performance of a digital
instrument (MIDI data)
Controller (keyboard, etc.)
Recording Playback
USB storage
device
USB storage
device
Tone generator
Sequencer
Keyboard performance (MIDI data)
Voice number (with what voice) 01 (grand piano)
Note number (with which key) 60 (C3)
Note on (when was it pressed)
and
note off (when was it released) Timing expressed
numerically
(quarter note)
Velocity
(strength at which it was played) 120 (strong)
Connecting a Computer or USB Device/What is MIDI