Apple Logic Express 9 - Manual (Page 1125)

To create a Physical Input object
µ
Choose New > Physical Input.
To make use of an existing object, drag it onto the relevant layer. This does not affect its
cabling.
Sequencer Input Objects
The Sequencer Input object represents the MIDI input of Logic Express. You can only have
one of these objects in the Environment.
MIDI events arrive at Arrange window tracks through the Sequencer Input object. If
nothing is cabled into the Sequencer Input object, nothing can be recorded in
Logic Express.
Typically, the Physical Input object is cabled directly to the Sequencer Input object but
other objects can be inserted between them. Candidates include a monitor, keyboard,
or cable switcher object (feeding various processors such as an arpeggiator, a delay line,
and so on).
You can also cable the output of simple or complex Environment processes into the
Sequencer Input object, in order to record the processed signal.
1125 Chapter 37 Environment Objects Reference