Paying attention while studying.?

I'm studying over English colonies and the Magna Carta and bill of rights and things like that, so I have a test in two days and actually i think i know a lot of it pretty well but it seems like i just don't want to study, buut.... i do. i know it sounds weird but how can i just make myself concentrate. Is there anything that people do before, after, or during to make them get the stuff there studying about in their brain, for example listening to music? or others. i just want to know how i can pay attention while studying