A standard Rolex has about 200 moving parts. The Patek Philippe on Jay-Z's wrist at the Met Gala has 1,580. Patek spent 8 years designing it. Then over 100,000 hours building the first one. About 11 straight years of someone working 24 hours a day, no breaks. It's called the Grandmaster Chime, the most complicated wristwatch Patek has ever made. The inner mechanism alone has 1,366 parts. It fits in a circle smaller than an Oreo cookie. The outer case adds another 214 parts, and the case alone took four years to design. In watchmaking, a "complication" is just any function beyond telling you the time. Most watches in the "grand complication" category have 5 to 7. This one has 20. When it launched, no wristwatch in history had combined that many. It tracks the phase of the moon, accurate to one day's drift over 122 years. It also has five different ways to chime: one that automatically rings the hours and quarters, one that rings only the quarters, one you press a button to hear the current time, one that rings whatever alarm time you set, and one that chimes today's date on demand. The last two had never existed in any watch before. Both were invented by Patek's own president, Thierry Stern, a trained watchmaker himself. The chiming makes this watch nearly impossible to copy. Inside each one are tiny coiled steel wires called gongs. A single watchmaker shapes and tunes each gong by hand, testing every note with their own ears. Just putting one chime mechanism together takes 200 to 300 hours. Then the watch goes into a soundproof chamber where the chime gets recorded and compared against decades of past Patek chimes. Only then is it brought to Thierry Stern. He listens. If he doesn't like the sound, the watch goes back. Sometimes more than once. A rejected watch can take 500 hours of rebuilding before he approves it. This watch holds four power springs in total. One is dedicated to the chimes alone, separate from the spring driving the time. Inside the mechanism is a ball bearing 7.2mm wide. It holds seven steel balls, each 0.3mm across, smaller than grains of fine sand. They handle 1,700 gram-millimetres of twisting force from the chime springs without slipping. The case has 11 holes drilled through it for buttons and pushers, and somehow none of them ruin the chamber that lets the chimes ring out clearly. The case itself flips around to show either of its two different dials. Fewer than five workshops on the planet can build something at this level. Patek Philippe is the one all the others measure themselves against. Jay-Z's version lists at $6.5 million. The unique steel version sold for $31 million at Christie's in 2019. It still holds the record for the most expensive watch ever sold at auction.