The grandfather clock at your grandmother's house
A grandfather clock chimes because it's two clocks in one case. One keeps the time. The other counts the hour out loud, on its own gears, with its own weight pulling it — and that second clock is the reason the sound exists, and the reason it goes wrong on its own schedule.
The case is the mechanism
The tall case isn't decoration. Inside hangs a pendulum about a metre long, taking one second per swing; that length is what makes it slow and steady, and the case is what gives it room and keeps the draughts off. Weights on cables or chains supply the push. English clockmakers worked the form out in the 1670s, and for two centuries the long case was the most accurate clock a household could own.
The strike train
The chime comes from that second mechanism — clockmakers call it the strike train. It doesn't read the hands; it counts. At the hour it releases its hammer onto a bell or a coiled gong, once for one o'clock and so on up to twelve. On an eight-day clock the train has its own weight and its own winding key, seen to once a week; the cheaper thirty-hour clocks were wound daily, by pulling a chain. Later a third weight was added to play the quarters — usually the Westminster Quarters, the tune we explained on its own page.
Why the name
Until 1876 these were just longcase clocks. Then the American songwriter Henry Clay Work visited the George Hotel in Piercebridge, in County Durham, and heard the story of the clock in the hall: two owners in turn, faithful through the first one's life, erratic after he died, stopped the week the second one did. He wrote "My Grandfather's Clock," the song made the name stick, and the Oxford English Dictionary credits it with renaming the whole category of clock.
Why the sound stays
The strike was the clock's whole point once. The dial was for whoever stood in front of it; the bell was for everyone else in the house. Three strokes meant three o'clock to someone in the kitchen with their back to the window. That's why the sound attaches itself to a place and a person — you didn't hear your grandmother's clock because you were watching the time. You heard it because it said the hour to the whole room, every hour, whether anyone was listening or not.
No winding required
Our Grandfather voice keeps the counted strike and drops the rest: one deep strike on the hour, counted out, no weights to wind, no case to dust. It's $5.99 once. Quarters if you want them, off if you don't, and quiet hours from ten to eight so it stays polite with the house.
And when a real one chimes at the wrong time, or counts thirteen — that's the strike train falling out of step with the hands. We've written about fixing that. If what you've inherited is a mantel clock instead, start there.
Read next: Why your grandfather clock chimes at the wrong time