Roland JUNO-D owner manual Performing with an external Midi device, About Midi, Channel messages

Performing with an external MIDI device

About MIDI

MIDI (Musical Instrument Digital Interface) is a standard specification that allows music data to be exchanged among electronic musical instruments and computers. By connecting MIDI devices that are equipped with MIDI connectors, you can play multiple instruments with a single keyboard, have multiple MIDI instruments perform in ensemble, program the settings to change automatically to match the performance as the song progresses, and more.

If you mainly use the JUNO-D as a standalone keyboard instrument, you may really not need to know much at all about MIDI. However, the following MIDI-related information is provided so you can play the JUNO-D using an external MIDI device, or master other advanced techniques.

MIDI connectors

The JUNO-D has the following two types of MIDI connectors.

fig.r10-01

•MIDI IN Connector

Performance messages from an external MIDI device are received here. When the JUNO-D receives MIDI messages, it will produce sound, change the sound it’s using, or perform other operations.

•MIDI OUT Connector

This connector transmits MIDI messages to external MIDI devices. The JUNO-D’s MIDI OUT connector is used for sending the performance data of the keyboard controller section, as well as the data used for saving various settings.

MIDI channels and multitimbral sound generators

MIDI transmits many types of data over a single MIDI cable. This is made possible by MIDI channels. MIDI channels allow messages intended for a given instrument to be distinguished from messages intended for another instrument. In some ways, MIDI channels are similar to television channels. By changing the channel on a TV receiver you can view the programs of different stations. This is because the television set has thus been directed to selectively display only the information being transmitted by a particular station. In the same way, MIDI also allows a device to select the information intended for that device out of the variety of information that is being transmitted to it.

fig.r10-02.e

The cable from the antenna carries the TV signals from many broadcast stations.

Station A

Station B

Station C

The TV is set to the channel of the station you wish to watch.

MIDI uses sixteen channels, numbered 1–16. Normally, receiving

devices should be set so they receive only the channels they need to

receive.

Example:

Set the JUNO-D to send on Channel 1 and Channel 2, then set sound module A to receive only Channel 1, and sound module B to receive only Channel 2. With this setup, you can get an ensemble performance, with, for example, a guitar sound from sound module A and bass from sound module B.

fig.r10-03.e

MIDI OUT	MIDI IN	MIDI THRU
Transmit channel: 1, 2	Receive channel: 1
	Sound
	Module
	A
MIDI keyboard	Receive channel: 2	MIDI IN
	Sound
	Module
	B

When used as a sound module, the JUNO-D can receive on up to sixteen MIDI channels. Sound modules like the JUNO-D, which can receive multiple MIDI channels simultaneously and play different sounds on each channel, are called “multitimbral sound modules.”

MIDI messages used by the JUNO-D

MIDI uses various types of messages to transmit a wide variety of information. MIDI messages are broadly divided into two different categories, those handled through individual MIDI channels (Channel messages), and messages that are not related to separate channels (System messages).

The JUNO-D mainly uses the following MIDI messages.

Channel messages

These are messages used for conveying what is happening in a performance. These comprise the bulk of MIDI messages.

Note On

This message is sent when a key is pressed. A Note-on message contains the following three types of information:

Note-on:A key has been played.

Note number: Which key was played

Velocity: The amount of force (velocity) used when the key was played.

The Note Numbers fall within the range of 0–127, with middle C (C4) as number 60.

fig.r10-04.e

Note name

C-1 C2 C3 C4 C5 C6 G9

0 36 48 60 72 84 127

Note number

Note Off

This message is sent when a key is released. When a Note-off message is received, the relevant note will be turned off. A Note-off message contains the following three types of information:

Note-off:A key was released

Note number: Which key was released

Velocity: The force (velocity) used during release of the key.

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