Yamaha CVP-900 Example Keyboard Data, Channel Messages

Using Your Clavinova with Other Devices

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CVP-900

The “controller” and “tone generator” in the illustration

above are equivalent to the piano in our acoustic

example. 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. However,

since the Clavinova features a built-in sequencer that lets

you record performance data, this recording equipment is

unnecessary. Instead, your digital instrument — 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 Clavinova 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 generator

is similar to that of the pianist and the piano — one plays

the other. Since digital instruments handle playback data

and the actual sounds independently, we can hear our

piano performance played by another instrument, such as

guitar or violin.

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 CVP-900 keyboard.

Unlike an acoustic instrument that puts out a resonated

note, the electronic instrument puts out information 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, the tone

generator plays the stored sampled note.

■Example Keyboard Data

Panel operations on the CVP-900, 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 sending

and receiving compatible Note, Control Change, Program

Change and various other types of MIDI data, or

messages.

The CVP-900 can control a MIDI device by transmitting

note related data and various types of controller data.The

CVP-900 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.

MIDI messages can be divided into two groups: Channel

messages and System messages.

■Channel Messages

The CVP-900 is an electronic instrument that can handle

16 channels (or 32 channels, when using the TO HOST

terminal). This is usually expressed as “it can play 16

instruments at the same time.” Channel messages transmit

information such as Note ON/OFF, Program Change, for

each of the 16 channels.

Tone generator

Sequencer

Keyboard performance

(MIDI data)

Even though it is a single musical instrument, the Clavinova can be

thought of as containing several electronic components: a control-

ler, a tone generator, and a sequencer.

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 (about how strong) 120 (strong)

Message Name CVP-900 Operation/Panel Setting

Note ON/OFF Messages which are generated when the

keyboard is played. Each message includes

a speciﬁc note number which corresponds

to the key which is pressed, plus a velocity

value based on how hard the key is played.

Program Change Voice selecting (control change bank select

MSB/LSB setting)

Control Change Volume, panpot (Mixing Console), etc.

MIDI data has the following advantages over audio data:

• The amount of data is much less, letting you easily store MIDI

songs to ﬂoppy disk.

•The data can be effectively and easily edited, even to the point of

changing voices and transforming the data.

The performance data of all songs and styles is handled as MIDI

data.