Yeah, they send you an email and say you have used copyrighted material and that it has been blocked. Then you can choose to audioswap the video and it´s up again, without the original sound of course. In your case it won´t be a problem because you have recorded everything yourself.
Watch this:
youtube.com/watch?v=ZGdIe-Vnp6g

But I think the program they use won´t notice if you´re playing over the original track because only two of my videos have been blocked, and in both of them I used the original song as a intro, you know, before the guitars kicked in. So there was only the original and no playing by me, so the program notice. That´s my theory anyway...