I don't know this girl from high school or anything... I had seen her around campus a couple of times, and then FB recommended her and come to find out we have.. what is it, 45 friends in common or something. I'll probably add her and just leave her a message as I'm not too fond of writing on peoples' walls. I'll just say that FB recommended her and that "she looked familiar- since we have a lot of choir friends in common, had she sung at All-State" or something along those lines. She doesn't REALLY look familiar, but it's a decent basis to start off with, and she doesn't have to know that.
She'll probably say no about the choir thing, but then we just go from there. Sound like a plan?