Just need help
Just need to know how i can maybe record a melody or something on this and use it in a music composition program...
there is no direct way to record from within Mouse Keyboard. You can use third party tools to record wave out -- either directly, or by connecting LINE OUT to LINE IN on your computer.
Also, you should be able to use a virtual MIDI port in order to connect MK directly with your composition program -- or a sequencer. See MK's help for how to do that.