. . . or at least it was, until ten minutes ago.
Janice Hardy has a good post on tone over on her blog. It's worth a read, because tone is a really horrible topic and Janice has some useful things to say on. This is unique.
In school, we always had to answer questions on the 'tone' of poems - theme, tone and technique, the three Ts. 'The theme of the poem is death. The tone of the poem is fearful. The poet creates a sense of fear by convincing us he is very scared. He does this by including a copy of his royalty statements which make the reader tremble and hide under the table.'
In other words, we knew exactly what tone was, but it wasn't always very easy to figure out why something made us feel the way we felt. Luckily, most poems are on school curricula because it is possible to talk about them, so while we usually could say something about word length or imagery, for the most part they were uninspired offerings. And we never talked about the tone of novels; we were too busy deciding what they said about the role of women in society during Decade X.
Then I went to university and studied English and we weren't allowed to feel things about texts anymore.
All good novels - and many bad ones - have a tone. It's an atmosphere, a feeling, a sense. It makes you, as Fry in Futurama once said, feel ways about stuff. And you know it when you see it. Creating it can be hard, which is where Janice's post may come in handy.
The hardest part, though, is finding out whether you've succeeded or not. I know exactly the tone I want for the novel but my brain supplies it naturally while I'm reading, so I have no idea if I achieved it or not. That's where beta readers come in handy :)