The author makes a mistake when describing open C tuning when he states "The Open C tuning is achieved by lowering the bottom E string to D. If we follow the authors instructions here we end up with a C9 tuning with the 9(D) in the bass or lowest note. Although this is an interesting possibility, I don't believe that it was the intention of the author. Now, obviously, to achieve a tuning of "C G C G C E", the bottom E string must be lowered two whole steps down to a "C", and when I say "bottom E string", I am referring to the string that is the lowest in pitch(Physically it is on "top" or "above" the other strings). Looks like this was just an oversight, but since this article is aimed at beginners, this should probably be addressed to avoid confusion among the uninitiated. The author correctly alluded to the fact that you will need to select heavier string gauges to use this tuning or your strings will be flapping in the breeze. Additionally, another notable tune which wasn't mentioned that uses this tuning, along with a capo, is 'Never Going Back Again' by Fleetwood Mac. I'm not trying to put anyone down, just want to correct what is probably just a typographical error. Hope this helps someone. Keep the great articles coming.