Logic Pro 9 User Manual - Help Library - Apple

Merging Regions (General Tools and Commands)
You can merge two or more selected regions (of the same type—audio or MIDI) into a
single region, making region handling easier, or as a creative option.
To merge two or more regions with the Glue tool
1 Select the Glue tool.
Glue tool
2 Click the regions that you want to merge. (If necessary, use the Shift key during selection.)
To merge two or more regions with the Merge Regions command
1 Select the regions you want to merge with the Pointer tool.
2 Choose Region > Merge > Regions (or use the Merge Regions/Notes key command).
This action merges all selected regions, even those on different tracks, into a single region.
To create several merge files, each on their own track
1 Select the regions that you want to merge on each track with the Pointer tool.
Shift-clicking, dragging to select, or Command-A may be useful for this step.
412 Chapter 13 Creating Your Arrangement