Apple Logic Pro 9 - Manual (Page 39)

Connecting Your MIDI Keyboard and Modules
If using a simple MIDI master keyboard without internal tone generation facilities, you
only need to connect the MIDI Out port of the keyboard to a MIDI In port on your MIDI
interface, using a MIDI cable.
Computer
MIDI interface
Out port
Keyboard
In port
If the keyboard can generate its own sounds, you should also connect the MIDI Out port
of the MIDI interface to the keyboard MIDI In port. If your MIDI interface offers more than
one MIDI output, connect any other tone generators (or other MIDI devices, such as
control surfaces that require bidirectional MIDI communication) to these.
Computer
MIDI interface Tone generator
Out port
Out port
Keyboard
In port
In port
In port
39 Chapter 2 Setting Up Your System