I spent a good part of Saturday whistling “Somewhere,” a melancholy note for lovely spring day thanks to the R142 subway trains rolling over Queens Boulevard. It turns out that even Tony Kushner enjoys this bit of coincidence, although his mechanical explanation is mistaken: it’s the electrical inverters, not the brakes, that make the sound.

I’d always been told that the distinctive (and rather more triumphal) tune on a certain generation of Montréal Metro cars (which turn up as the opening to “Il Fait Beau Dans le Metro“) were made by the air brakes, but it turns out that they, too, are made by the electrical equipment.

The CTA’s new AC-propulsion trains, although also built (like the R142 series) by Bombardier, don’t have a distinctive sound as they leave the station.