Apple Logic Pro 9 - Manual (Page 26)

MIDI Regions and Events
MIDI regions, by comparison, actually contain MIDI data events. They are not related to
information stored in external files. MIDI regions can be saved as individual files, but they
can also be, and generally are, stored as part of the project.
MIDI region
MIDI note events MIDI controller events
The MIDI data events stored within MIDI regions include note, controller, program change,
and other information. These data events represent MIDI performances that you have
recorded into Logic Pro. MIDI performances are generally created with a MIDI keyboard,
but can also be generated with MIDI controllers, MIDI guitars, your computer keyboard,
or the mouse.
MIDI data events can be affected as a group by processing the MIDI region that contains
them. Such processing includes: transposition, quantization (timing correction, which is
similar to the spell checker of a word processor, when dealing with the language of music),
timing delays, and more.
You can also edit individual events within a MIDI region. You do this by opening the
region in one of the MIDI editors. These windows allow you to precisely alter the position,
length, and pitch of MIDI note events. Other MIDI event types can also be altered in
various ways. You can freely enter MIDI data with your MIDI keyboard, the mouse, or
computer keyboard in these editors.
For more information about MIDI and MIDI event types, see Introduction to MIDI Editing .
26 Chapter 1 Introducing Logic Pro