some people mod the guitars to be able to play guitar synth notes. some people pay big bucks for a really good midi program. but i like many other cheap-o's out there dont like to pay for stuff and so i give you my instructable.
-pc (sorry mac owners. you can do it to but you will need to find another joy to key)
- xbox 360 guitar xplorer controller (sorry)
- or rock band strat