Editor's Note: What Goes Around

The post-war history of music playback systems has had a circuitous evolution

This weekend’s post began in the shower, where the best ideas spring forth. For some reason, a shower sets your head in neutral. Washing and shampooing are auto-pilot chores, freeing up your brain to wander. The following came to mind last week [photo above of Central Park by Marc Myers]:

Since the end of World War II, in 1945, major innovations in musi…