Yamaha MU80 Owner's Manual page 123

Basic Concepts
The XG format maintains the universality and compatibility of the MIDI and GM standards
while significantly increasing the range of expressiveness. It is designed to ensure data conti-
nuity, and to provide equipment manufacturers with considerable flexibility in designing ma-
chines that satisfy its requirements.
Specifically, the XG format does the following.
Enables production of extremely expressive sound data
Significantly expands available voice types and variations
Supports future compatibility of sound data among musical instruments, computers, and
other devices
Ensures that data will remain fully usable well into the future
Supports standardized handling of new types of effects-inclusive data (such as karaoke
data)
The XG format is founded on the following three principles:
Compatibility
Scalability
Expandability
1 Compatibility
Any XG machine, regardless of model or manufacturer, will provide faithful reproduction of
any XG sound data. Because the XG format maintains downward compatibility with the GM
format, XG machines will also provide correct reproduction of GM sound data.
2 Scalability
Although the XG format provides detailed and extensive specification of voice sets and
voice changes, it does not require XG machines to support the full range of functions.
Designers are free to develop a wide range of products to meet various cost and perform-
ance objectives. Each XG machine will replay XG data in accordance with the machine's
level of sophistication. If a model does not support a variation voice, it will automatically
play the corresponding basic voice instead. If a model includes a graphic equalizer, it can
take full advantage of graphic equalizer functions so as to control frequency characteris-
tics to best suit the musical genre being played — from lively rock to soothing classical.
3 Expandability
The XG format remains open to enhancements and extensions that will allow it to remain
in step with future product developments.
Additions to the GM format
The XG offers the following extensions to the GM format.
Voices: The GM format supports 128 voices. The XG format provides for Bank Select
messages that significantly expand the number of voices supported.
1) Voice Extension by Bank-Select LSB
Variations of basic GM voices are stored in banks. To select a variation, specify the de-
sired bank by sending the appropriate Bank-Select LSB value. Each bank is associated
with a specific type of variation, so that voices are easy to locate.
APPENDIX
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