Yamaha PSR-270 - page 93

MID I FUNCTIONS

The PortaTone is MIDI-compatible, featuring MIDI IN and MIDI OUT terminals

and providing a variety of MIDI-related controls. 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-270.

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 classi-

cal 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?

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-270

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.

Voice number (with what voice) 01 (grand piano)

Note number (with which key) 60 (C3)

Note on (when was it pressed) and Timing expressed numerically (quarter note)

note off (when was it released)

Velocity (about how strong) 120 (strong)

Example of Keyboard Information

Acoustic guitar note production Digital instrument 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.

Tone Generator

(Electronic circuit)

Sampling

Note

Playing the keyboard

Sampling

Note

The MIDI functions cannot be used in the Song mode.