You can just plug the audio out of the MicroKorg into the audio input jack of the Mac and it will work. However to get better audio clarity and more potential out of the MicroKorg, I recommend getting an external audio interface. There are many of them on the market and you can go around trying different ones out till you find the right one or you can take the advice of a broke Alien. Never ever ever ever ever buy a M-audio interface for Mac. I lost a one year old, just of warranty, MacBook Pro to one of these garbage devices. It fried the Motherboard! I should’ve known better, I have a friend who worked there 2 years ago and he told me that the engineers there do a lot of drugs! Even at work! Not professional! I finally got everything back in order and bought an Alesis IO 26. This is probably overkill for what you are doing. So I recommend doing some research and find a device that has MIDI and Audio handling capability. This way you get the ability to sequence MIDI and record audio.