Yamaha MU50 Owner's Manual page 55

MULTI MODE
EG Parameters
1) Short Attack, Decay, Release times:
2) Long Attack, Decay, Release times:
Graphically shows EG Attack Time setting for each Part.
46
Level
Attack Decay
Max.
Min.
Key is pressed
Level
Attack Decay
Max.
Min.
Key is pressed
Even though the key is held for the same length of time in both examples,
the sound of the second example slowly reaches full volume and decays
over a longer time. It also sustains longer after the key is released.
Keep in mind that the EG parameters affect each other, and are af-
fected by how long a note is held. For example, if Decay is set to a
low value and the note is held for a long time, you may not be able
to hear changes made to the Release parameter.
Selected Part and MIDI channel
Release
Time
Key is released
Release
Time
Key is released