Many people believe resonance to be very rare, when in fact every single timekeeping device (yes, even quartz) is a resonant mechanism. But clocks and watches featuring resonance as we generally understand it in watchmaking are few and far between. In the last few decades, less than a handful of highly skilled watchmakers have taken up the challenge of creating a resonance watch. Here, Joshua Munchow looks at the pros and cons of the different approaches taken by the three leaders in this technology.