"MIDI"  stands  for  "Musical  Instrument  Digital  Interface."  It  is  an 
international  standard  that  allows  electronic  musical  instruments  to 
communicate  with  each  other,  using  a  simple  cableconnection.  The 
Mark-Pro TWOi is compatible with other MIDI instruments.  
On the rear panel are two MIDI ports:
          MIDI In receives MIDI messages from
 
other equipment.
          MIDI Out sends MIDI messages to other equipment.
MIDI  cables provide  the  connection between  the  MIDI ports  of  one piece 
of  equipment  and those of another. To keep things simple, there are only 
two valid MIDI connections: Out to In, and In to Out.
The  simplest  use  of  MIDI  is  to  play  two  instruments  at  a  time  from  the 
keyboard  of  one  of them.  This  is  known  as  a  "Master-Slave"  connection. 
Use  a  MIDI  cable  to  connect  the  MIDI  Out  port  of  the  "Master"  (the 
instrument whose keyboard you'll play) to the MIDI In port of the "Slave".
Mark-Pro TWOi
MIDI
MIDI
MIDI OUT
 MIDI IN
External MIDI device
MIDI Connection