Have you ever gone to a dance by yourself? No? You annoyingly popular human, you. Fine. Just pretend that you have. Imagine what it’s like. Picture this: You’re walking down a dimly lit street, trying to look purposeful and also as if you’re going to an enjoyable event and not a crime scene investigation or your own execution. This is difficult, as you are alone. If you walk slowly, you appear up to something. If you walk quickly, you seem frenzied and paranoid. If you smile, or, worse, if you laugh and chat to yourself, someone’s sure to call the police. If you frown or gaze steadfastly into the distance, someone’s sure to call the police. The point is, it’s not easy. Finally, you see figures ahead of you and your ears pick up the first lively notes of a polka. This may be different for you, depending on where you live, but I happen to live in a town that enjoys polka music...