Yamaha MU15 Owner's Manual page 5

Your MU15 package should include the items listed below. Make sure that you
have them all.
• MU15
• Owner's Manual
GM System Level 1
"GM System Level 1" is a standard specification that
defines the arrangement of voices in a tone generator
and its MIDI functionality, ensuring that data can be
played back with substantially the same sounds on any
GM-compatible tone generator, regardless of its manu-
facturer or model.
Tone generators and song data that meet the "GM
System Level 1" bear this GM logo.
XG
"XG" is a tone generator format that expands the voice
arrangement of the "GM System Level 1" specification
to meet the ever-increasing demands of today's com-
puter peripheral environment, providing richer expres-
sive power while maintaining upward compatibility of
data. "XG" greatly expands "GM System Level 1" by
defining the ways in which voices are expanded or
edited and the structure and type of effects.
When commercially available song data bearing the XG
logo is played back on a tone generator which bears the
XG logo, you will enjoy a full musical experience that
includes unlimited expansion voices and effect func-
tions.
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