Here’s an excellent article on genre from The Atlantic. Don’t misunderstand the title, though–Berlatzky’s idea here is that genre is in itself a shaky construct.
Why is that important? Well, you’ll need to read the article to find out.
“That’s why the argument that some books transcend genre is incoherent: Genres aren’t conceptually solid enough to be transcended. Any genre is going to be made up of things that both fit and don’t, and over time those things will change and shift.”