The lost wax casting method has been in existence for nearly 5000 years, being used to create all manner of things including jewelry, vessels for liquid, and sculpture. The process consists of carving the item to be cast in wax, then packing it with clay. Once the clay hardens, it’s heated up to melt away the wax. Molten metal is poured in its place, creating the cast.
The art of casting carillon bells has been perfected over many centuries. Using a bronze alloy with a specific ratio of copper to tin, they’re cast with the ideal shape and thickness to produce a clear ringing tone. Once cast, they’re turned on giant lathes to have material shaved off at just the right spots during the tuning process.
Bellfounders such as the Paccard Fonderie des Cloches have been making bells in much the same way for well over 200 years. A notable carillon in the US is at Yale University, which houses 54 bells and can be played similarly to a piano, albeit with gigantic levers attached to each bell. Students chosen as carilloneurs are allowed to play whatever tunes they wish, from the Beatles to Scooby Doo, tolling across New Haven from the top of Harkness Tower.