rrodri31 wrote:I hate to be a pest but how would I go about that? If it's possible/feasible, that is.
you need an audio interface to convert analog signals, like the outputs of your keyboard, to digital ones, such that they can be recorded by your computer.
something like an mbox:
http://www.avid.com/US/products/mbox
or a scarlett 2i2:
http://us.focusrite.com/usb-audio-inter ... arlett-2i2
After getting and properly installing one of these, ableton will recognize it as an audio interface device and you can route audio out from it to things like Monitor Speakers, Headphones, or Outboard FX Devices, as well as route input signals into it from things like Synthesizers, Guitars, Microphones, External FX Boxes, Turntables and more. Make sure you get one with "pre-amps" so you can record microphones,. The ones cited above are so equipped.
But seriously, do yourself a favor and study this for a bit. Go down the rabbit hole.:
http://tweakheadz.com/guide-to-home-and ... c-studios/