Regarding based on real events, how about 9-11, the great depression, terrorist attack, some kind of fall of man? 9-11 would be real doable, actually.
@theme song question ; sometimes I have a song, sometimes I have none, sometimes I have several. Sometimes I base characters around songs, sometimes I create playlists for my favourite characters. Oh my god , making my playlist for a character is heaps fun.
Actually, to get in character and try and thing the way they do, sometimes when I go out places alone, I try to walk and react as they would. Take Oakley, one of my favourite characters, I stand up quite straight, make sure my hair is perfect an suck in beautiful surroundings, just as she does. I get nervous at loud notices, make my voice all gentle and fragile and I never forget my manners (which I don't do anyway!!) Sometimes I dress like her (which is hard, because I don't have a lot of summer dresses (aka I have none)) so I can just be her for a day. It's really cool, I suggest everyone give it a shot. It can tell you how different your character is from yourself.