My question is pretty simple, but I'm also wondering if you could give me some behind-the-scenes info on this as well. I want to include lyrics to a song (written by someone else) in with my manuscript. At what point should I mention this to the agent? What do agents do to secure permissions, and (if stipulated) what's the typical payout for the original author of the song/poem/whatev's? I know the latter is a bit ranging, but I'll settle for an anecdote.
For starters, it's not your agent's job to clear permissions for song lyrics. It's yours. And song lyrics, depending on the song, can be expensive. And the other possibility is you won't get permission at all.
Quoting lyrics is a rat's nest of contradictory information. There's the common internet rule "quote two lines and you're fine" but if the song is only ten lines, you're not fine.
And the liability for permission, or use of any material that's not yours, is on you, not the agent or the publisher. Use it without permission, get caught, and the publisher doesn't have to defend the lawsuit, you do.
When clients of mine want to quote song lyrics, I advise them to keep it to one line, and use it as an epigraph.
When I advise them of the problems that come with getting permissions, they often times find they can do without those quotes very easily.
The good news is OLD songs, pre-1920, are in the public domain.
To answer your question: you don't need to tell anyone you're quoting song lyrics until you have a contract for publication. However, it's a very good idea to let your agent know before she starts the contract negotiatons. She may be able to work some magic here.
At this point you'll need to secure permission to quote the lyrics. You'll have to pay for it too. (It's hard to secure permission before sale because the rights holder often wants to know the print run, format, and territories covered in the deal)
This is the general clause that covers that:
The Author shall, at the Author's expense, deliver valid written permission from the proprietor (ie the rights holder) for the use of any copyrighted material in the Work (such permission to extend to all rights granted herein, including electronic publication) and all necessary illustrations, maps, charts, and photographs for the Work, on or before the delivery date set forth in subparagraph 2(a). Author is responsible for paying all permissions costs on or before the delivery date set forth in subparagraph 2(a). The Publisher is not responsible for publication delays resulting from Author's negligence in obtaining and paying for permissions, or in presenting valid written permission to the Publisher.