Midi Functions; What Is Midi - Yamaha PortaTone EZ-30 Owner's Manual

MIDI Functions

The EZ-30 is MIDI-compatible, featuring MIDI IN and MIDI
OUT terminals and providing a variety of MIDI-related con-
trols. 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 EZ-30.

What is 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.
Based on playing information from the keyboard, a sampling note stored in the tone
generator is played through the speakers.
As shown in the illustration above, in an electronic instrument the sampling note (previ-
ously 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
EZ-30 keyboard. Unlike an acoustic instrument that puts out a resonated note, the elec-
tronic 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)
20 (strong)
R
Sampling
Note
75