GAIA Exploring Sound (PDF) - Roland Corporation Australia

Now switch on TONE 2, select it for editing, and follow this Action
List:
Audio 8.7 Oscillator Sync 3
Figure 8.8 Oscillator Sync 2
To understand what is happening here you need to realize that
you have set the Pitch of TONE 1 higher than that of TONE 2.
Now when you play the keyboard you will have a combination of
two sounds. One playing the notes as expected, the other rising
and falling in pitch.
Figure 8.9 Sync Diagram
Audio 8.6 Oscillator Sync 2
Notice that TONE 1 always begins by climbing in pitch, this is
because we have selected Key Trigger.
Now the exciting part; Press the Mod switch in the Oscillator
section to select Sync. It doesn’t matter if you have TONE 1 or
TONE 2 selected. The Mod switch affects them both.
Play the keyboard and you will get a classic synthesizer sound
from the early 1980s, one that is still used today.
Then, by turning on the Sync function you are asking TONE 1 to
try to synchronize it’s Pitch to that of TONE 2.
Take a look at this picture of the two TONES:
You can see that every time Oscillator 2 crosses the zero axis it
“tells” Oscillator 1 to “start again.” As a result Oscillator 1 exhibits
the character of both pitches. It sounds like it is in tune with
Oscillator 2, but also has some of the character of the higher
pitch.
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