I see nothing wrong with the "the year in music 1981" entries. Most of what goes there would not go in a "1981" entry. It would be fine to link Joan Jett's "I love rock and roll" from the rock and roll anthem page to the year in music, but I don't think you'd link it to 1981.
Nor do I see anything wrong with having parallel entries for "the year in dance", "the year in books" or whatever anyone might want to put together.
I agree. I'm busy putting the year in books pages on my own website. By the time you go through the bestsellers for a year, important books that weren't best sellers, link to authors bios and website, you have a pretty intereresting page that includes a lot of detail that would just clutter up a year page.
Fred