It’s a curious thing about books and stories: within the first few lines or paragraphs, readers implicitly know the mood of the story. They know what kind of story it’s going to be. But if asked, the reader would not be able to identify anything concretely as an indicator of the mood. The word choices and sentence structures indicate mood, but usually only other writers can pick up on it.
I’ve noticed the same thing when it comes to speaking in public or teaching. The room has a mood. Stand-up comics know this because they must “read the room” or remark that it’s a “tough room.”
I find this very interesting because the mood of a story isn’t just one character, even the main character. It’s the collective character of the book. The setting, characters, and narrative style dictate it.
Mood tends to be associated with the writer, as well. Stephen King is the master of horror. And King was readily identified in his Bachman books because of the distinctive style and mood of his books, even though King claims those were a darker kind of book.
This makes it difficult for writers to be able to write in more than one genre. Can the young adult fantasy author transition to noir mystery? To erotica? Good writing is good writing, but audiences are different across the board. Someone who was beloved in one genre, may not be so well received in another. And while fans can migrate, they, too, may not appreciate the mood and rules of the new genre.
It makes for a sticky situation, and makes me wonder about my own writing because I have story ideas across genres.