Device Setup submenu
        How to get there
        From the MIDI Menu, choose Device Setup.
        What it does
        These commands allow you to edit MIDI setup  settings.
         
        
            - MIDI Setup. Choose this command to open the MIDI Setup dialog box where you can edit 
 a number of settings pertaining to your MIDI interface setup. See MIDI Setup dialog box.
- MIDI Thru. If you prefer to use one 
 keyboard as a controller and another as the sound source, MIDI Thru must 
 be on if you wish to hear notes from one device as you’re entering them 
 on another.
- Open 
 Audio MIDI Setup. Choose this command to open OS X’s Audio MIDI Setup 
 dialog box where you can adjust settings for MIDI input and playback. 
 For example, you might use Audio MIDI Setup to assign a name to the port 
 used to connect your external MIDI device. (The port’s name will appear 
 accordingly in SongWriter’s MIDI Setup dialog box).