Midi Functions; What's Midi - Yamaha DRX-730BL Owner's Manual

MIDI Functions

In the rear panel of your PSR-730/630, there are MIDI terminals (MIDI IN, MIDI OUT), a TO
HOST terminal, and a HOST SELECT switch. By using the MIDI functions you can expand
your musical possibilities. This section explains what MIDI is, and what it can do, as well as
how you can use MIDI on your PSR-730/630.

What's MIDI?

No doubt you have heard the terms "acoustic instrument" and "digital instrument."
In the world today, these are the two main categories of instruments. Let's consider an
acoustic piano and a classical guitar as representative acoustic instruments. They are
easy to understand. With the piano, you strike a key, and a hammer inside hits some
strings and plays a note. With the guitar, you directly pluck a string and the note
sounds. But how does a digital instrument go about playing a note?
Acoustic guitar note production
Pluck a string and the body resonates the
sound.
As shown in the illustration above, in an electronic instrument the sampling note
(previously recorded note) stored in the tone generator section (electronic circuit) is
played based on information received from the keyboard. So then what is the
information from the keyboard that becomes the basis for note production?
For example, let's say you play a "C" quarter note using the grand piano sound on
the PSR-730/630 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 sampling note.
Example of Keyboard Information
Voice number (with what voice)
Note number (with which key)
Note on (when was it pressed) and
note off (when was it released)
Velocity (about how strong)
Digital instrument note production
Tone Generator
L
(Electronic circuit)
Sampling
Note
Playing the keyboard
Based on playing information from the keyboard, a
sampling note stored in the tone generator is played
through the speakers.
01 (grand piano)
60 (C3)
Timing expressed numerically (quarter note)
120 (strong)
R
Sampling
Note
119