Apple Logic Pro 9 - Manual (Page 1065)

• Sequencer Input object: This represents the door into Logic Pro for incoming MIDI events.
In Logic Pro, incoming MIDI events (which arrive at the Sequencer Input object) are always
directed to the selected track in the Arrange area’s track list, where they can be recorded
in MIDI regions.
The events played by the track region are mixed with incoming events (if any), and sent
to the Environment object that the track is routed to.
From here (the multi-instrument object), the events are directed to a MIDI output (see
Creating Direct Output Assignments ).
You can insert objects into the signal path between the Physical Input object and the
Sequencer Input object if you wish (a MIDI monitor object, for example, which allows you
to see incoming MIDI events).
You can also insert objects between the arrange track and its destination object, enabling
other Environment processing. The arrange track itself is not represented by an
Environment object, but you can use the Track Assignment menu to route the track’s
output to an Environment object.
1065 Chapter 36 Working in the Environment