Worst Kept Secrets

Ok, I’m starting to get a little freaked out by this. A couple of nights ago, I got over twenty blank text messages from the same Nanjing cell phone number, which I didn’t recognize. I figured that a student probably had my number and just sat on his/her phone or something. But then the same number’s been calling me all weekend, and I’ve answered a couple of times. When I answer, all I hear is some beeping and a few measures from Fur Elise playing over and over again. Not the famous part of Fur Elise, either, but the rising triplet pattern in the middle, and it cuts off right before the crazy bit where it comes crashing back down - in other words, not the part that it makes sense to play on a loop over and over. Does anyone know what is going on here? It keeps calling me over and over again. The other weird thing, which is probably just coincidence, is that the last four digits match my parents’ number.

UPDATE: Ok, it’s probably just a phone number phishing scam and not some kind of poltergeist (even though it was the EXACT two measures that nearly did my head in when I was learning the piece in sixth grade - I’m actually completely convinced it’s a poltergeist, but for the sake of appearing like a reasonable person I’m offering an alternative explanation).