Where am I? Train melodies

When your train is about to depart a station anywhere on the JR East lines, you will hear a melody to tell you the train is departing. The train lines and stations have distinctive jingles which remind you where you are and whether you are on a local or express train bound for wherever.

I spend a lot of time on the Joban express and local lines, and sometimes see train nerds with microphones held to the station platform speakers. I thought, perhaps they are collecting evidence to lodge a noise pollution complaint. But it turns out they were recording and carefully cataloguing the hundreds of train melodies. An interesting hobby.