Choosing an External MIDI Interface
There are a wide variety of MIDI interfaces available. When you select a MIDI interface,
consider the following:
 You need a MIDI interface that is compatible with Mac OS X.
 Most interfaces connect to your computer via the USB port, although some PCI and
FireWire audio interfaces include MIDI ports.
 You should purchase a MIDI interface that supports the number of control surfaces
you need, plus any additional MIDI equipment you may want to connect to
your computer.