"Notes From the Underground" by Nicholas Thompson: "The New York City subway has two good places for musicians to perform: the platforms where the trains stop, and the hallways leading between platforms and up to street level. The advantage of a hallway is that everyone passing by hears you for a few seconds; in a platform, you get far fewer people, but they hear you longer. Hallways, it turns out, work great for playing music that's instantly familiar." [permalink]