Yamaha VP-1 Owner's Manual page 108

If Scene Copy Mode is set to "no swap", the VP1 copies the element without
swapping the scene data.
If Scene Copy Mode is set to "confirm", the VP1 prompts you to select between
"swap" and "no swap" before making the copy.
Voice A01
Initial scene = S2
COPY
Voice A02
Initial scene = S1
• Here is a typical case in which you might want to use the "swap" option. Assume
that the destination voice consists of a single element (element 1), that the voice's
initial scene is set to Scene 2, and that the element's scenes are set up as follows.
Scene 1: LFO set for extreme oscillation
Scene 2: Normal sound (initial scene)
Scene 3: Low-mid range cut off; faint sound
Now assume that the element you want to copy has its scenes set up as follows, and
that it belongs to a voice whose initial scene is set to Scene 1.
Scene 1: Normal sound (initial scene)
Scene 2: LFO set for extreme oscillation
Scene 3: Extremely low, droning sound
If you copy the above element into Element 2 of the destination voice using "no
swap", the resulting scene arrangement will probably be inappropriate. The
destination voice's initial scene (Scene 2) will produce a normal sound for Element
1, but an unusual oscillating sound for Element 2. If you execute a "swap",
however, the initial scene (Scene 2) will produce a normal sound for both elements,
while Scene 1 will produce an oscillating sound for both elements. (
REFERENCE: 2-13)
Element 1 S1 settings S2 settings S3 settings
Element 2 S1 settings S2 settings S3 settings
Element 3 S1 settings S2 settings S3 settings
Element 4 S1 settings S2 settings S3 settings
Element 1 S1 settings S2 settings S3 settings
Element 1 S1 settings S2 settings S3 settings
Element 2 S1 settings S2 settings S3 settings
Element 3 S1 settings S2 settings S3 settings
Element 4 S1 settings S2 settings S3 settings
Concept of Swapping
Editing Functions
SWAP
REFERENCE
Chapter 1 PLAY Mode 1 - 39