Apple Logic Pro 9 - Manual (Page 416)

When opened, folders look just like the Arrange area and track list in a project.
All regions in the folder are routed to, and played by, the channel strips set in the folder’s
track list, just as they would at the top level of the Arrange window.
Note: If you drag a folder to a track that is set to an instrument channel strip, its entire
contents (all MIDI regions within the folder) are played by that instrument. This usually
only makes sense if the folder contains tracks for a given instrument or instrument type,
such as a drum kit or generic string sound. This technique provides a quick way of listening
to a string arrangement, if some of the intended sound sources are unavailable, for
example.
For example, a brass section folder could contain trumpet, saxophone, and trombone
tracks, or perhaps 14 tracks of drum instruments, which you may want to treat as a single
drum pattern region.
In the same way, your entire project, including all tracks and regions, could itself be a
folder, appearing as a gray beam in an arrangement. In this way, you could arrange several
projects for a concert.
This is not all that folders can do. You can use folders to represent song choruses and
verses, for example. As in the Finder, you can place as many folders as you like within
other folders, and within yet more folders (for the instrument groups within the different
parts of the song, as an example), with no limit to the number of levels you can create.
Another possible use might be to store different arrangements of a project in different
folders, allowing you to switch between them rapidly.
Packing and Unpacking Folders
You can pack selected regions into a folder, or create an empty folder and add regions
to it.
To pack selected regions into a folder
1 Select the regions.
2 Choose Region > Folder > Pack Folder (or use the corresponding key command, default
assignment: Shift-Command-F).
If all selected regions are located on different tracks, a new folder track is created.
416 Chapter 13 Creating Your Arrangement