WASHINGTON DC, USA—On my first night in D.C., a family member takes me up to National Cathedral. From then on, I'll use the Cathedral's towers to orient myself in an unfamiliar city: at the right angle, they appear unexpectedly in a skyline that still makes no sense from the ground.

That night the summer’s humidity hasn’t yet kicked in, and the air is getting cool, the Cathedral’s distant silhouette imposing against a setting sun. We follow the sound of its bells across the city and into the parking lot, where the echoes reverberate through and out of the building, suddenly tangible and thick.

The pinnacles of the central tower are still secured from scaffolding, damaged after a 5.8 magnitude two summers ago shook up stone, and its metal beams poke into the sky.

Inside, past the pews, we get on an elevator—it’s tiny and old, with manual doors of metal grates—and speed upward past the stained glass windows, into one of the cathedral’s slim towers. Up another spiral staircase, a small group inside the bell-ringing chamber pulls on the ropes connected to the Cathedral’s ten bells in a room above.

The ropes shoot up, then down, the noise projected outward so much greater than the person holding the cord—thousands of pounds of metal between two palms.

Bell-ringing is less abstract than that, though; it's strictly mathematical. Songs are written out with numbers that indicate the order in which each bell should be rung. Ringers perform the complex patterns from memory, guiding the bells through a 360-degree rotation while coordinating with the others, and if they mess up, it’s no well-kept secret: An entire city hears.

But from below, I think, you never think about the hands that project music into the grid of the streets, the systems that keep a city in time. The sun disappears like it always does, and the bells stop when it hits 9:00.