I'm doing a course on he historiography of music, which mostly consists of reading books like this. One topic that comes up a lot, in traditional music history, is periodization: how to divide history into blocks, which for some reason is considered important.
Our teacher, obviously stuck in the usual elitist Eurocentric (aka "western") tradition, talked about the length of periods, and mentioned how some claim you can have sub periods as short as maybe 25 years! Some people claim Sturm und Drang as a subperiod even! Obviously, as a pop genre buff I scoff at that sort of numbers. In pop music discourse it's not uncommon to have genres that everyone agrees only lasted for five years or so - grabbing something out of thin air, say, post-punk.
This got me thinking. What, when it comes to generally used and agreed-upon genre names, is the shortest-lasting genre ever? Tentatively I've started thinking of really short genres with definite starts and stops, and I've come up with Rocksteady's two short but incredibly, incredibly creative years as a first shot. But surely there must be even shorter ones?