I got an interesting idea... it is quite simple. I am currently writing the introductory chapter of my new project. And I always have the bad habit of writing some single sentences detached from paragraphs, usually in cursive. So he though, with tears in his eyes Well, not really. But I really like putting sentences like those in between some paragraphs. Now my idea is to connect those sentences and form a poem that ends with the first chapter. At the end, I would join all the sentences, and the reader would think "ah, I've read that before! so that's what those strange sentences meant!" What would they think, in spite of all that happened?
First off, please don't use italics (or alternative fonts) to set them apart from the narrative flow. There is no justification for font changes in a manuscript, and there are specific uses for italics; that isn't one of them. The only construct I can think of that would fit your purpose is the block quote, text indented relative to the body of the text, but for single line insertions, it will just look like random short paragraphs. It's a gimmick, and would be distracting for the reader. I see no benefit to it. Avoid stunts. They may seem like an attention-grabbing innovation, but they quickly wear thin and become a mere annoyance.
woah that was harsh. But better heard here than from an editor... thanks, I'll take that in mind from now on!
Creative idea. I like it for some reason, but I think Cogito is right. It can annoy the reader. You could try it out and when you have it read by a couple people, you could ask them what they thought, because if the poem ends up done really well you could keep it in. It all depends on what it looks like in the end, and if you don't like it, or have had a lot of criticism, you could take some time and take it out.