It had been many years since the clock and bell atop Cambridge City Hall actually worked. The hands lay still, the belfry silent. When city leaders began revitalizing Central Square in the 1990s, it was hardly the symbol they wanted: A functional municipality couldn’t have a dysfunctional clock tower. So Cambridge brought in a clock restorer, David Graf, to give new life to the intricate 1870 mechanism, built by E. Howard Watch & Clock Co. of Waltham. (The 2-ton bell had come from the Meneely Co. in West Troy, New York.) Neighbors debated questions like how often the bell should ring, how late, and even if it should ring again at all. Today, high above the lively square, the clock marches on, triggering a hammer that strikes the bell on the hour, its clang reverberating across the city from 9 a.m. to 9 p.m. It’s a purely mechanical — and delightfully anachronistic — system, so Graf returns regularly to wind and maintain it. An inscription on the bell reads in part: “Cheerfully I ring the hour / From my home within the tower.” One neighbor, Paul Schierenbeck, described the chime to me this way: “It’s a wonderful sound that means ‘home’ to me.”WHAT DO YOU HEAR? Scott Helman is a Globe Magazine staff writer. Send ideas to email@example.com. Follow him on Twitter @swhelman.