Apple Logic Pro 9 - Manual (Page 348)

When opened, folders look just like the Arrange area and track list of a project.
Alias and Cloned Regions
Aliases can be created for MIDI regions and folder regions. A MIDI or folder region alias
is like an alias in the Finder. It looks like a region, but contains no actual data. It is just a
reference to the data of the original region—a virtual reflection of the original. You can
easily recognize an alias because its name is written in italics.
If the data in the original (source) region is altered, all aliases of the region are affected
immediately. Each alias has independent region parameters, however.
Clones can be created for audio regions (by Option-Shift-dragging). These are comparable
to MIDI region aliases, but differ in that adjustments to the start or end point of any cloned
region affects all other cloned regions in the same way. Adjustments to the source region
do not affect clones.
You can, of course, create independent copies of audio regions (by Option-dragging),
which can be adjusted without affecting other copies or the source region.
See Creating Your Arrangement for further details.
MIDI and Audio Regions Compared
The following overview sums up the main differences between audio and MIDI regions.
Audio regions MIDI regions Feature
No. Audio regions are just references to parts of
audio files. Yes Composed of discrete
data
Yes Yes Can be named
348 Chapter 12 Getting to Know Regions