Yamaha TG500 - Manual (Page 177)

165
VOICE EDIT MODE / VOICE
VOICE COMPARE
VOICE COMPARE
The voice compare function makes it possible to compare the sound of a voice
being edited with the same voice prior to editing.
To temporarily recall the original voice data while editing, press the
[EDIT/COMPARE] key. The [EDIT] LED will flash, indicating that the compare
mode is engaged. Press [EDIT/COMPARE] a second time to return to the edit mode
and the voice being edited.
[EDIT/COMPARE]