Ahab’s advice about the quantity your are quoting is good. I’ll add a bit more.
Fair use also hinges on how you’re using the material. If you’re a music professor writing a scholarly article in which you quote the song, line by line and commenting on what each means, you could use every bit of it.
On the other hand, if you’re writing a novel and simply want to include a scene in which a character sings that verse to himself or others, you’re probably out of luck. What you’re doing is no different from including that song in a movie. You need permission and that may mean payment
I’d suggest making a reasonable effort to locate who owns the rights and contacting them. It might be the writer’s family and they might be flattered by the attention, giving permission for free. If not, you’ll probably be entering the domain of greedy lawyers, where it’d be wisest to give up.
Then, as Ahab has suggested, you’d be better off finding lyrics old enough to be in the public domain.
I might add that the hassles of getting permission are one reason why long copyright periods may actually not benefit most writers. The typical writer enters a period in which his or her writings are little read since they’re no longer contemporary or being promoted by a publisher who, at best, considers them “backlist.” They then get a second chance when the copyright expires and anyone can publish—or today more likely post online—what they wrote.
For an illustration, go to a public domain website like this one:
loyalbooks.com
And look at a list of their most popular books. All or almost all will be quite well written, but would be little read today because there’s no one promoting them. Make them free and easy to get, though, and quite a few people read them or listen to them as audiobooks. People even help to create carefully proofed texts and read for audiobook versions.
For an example, I’m current listening to this audiobook as my bedtime story:
loyalbooks.com/book/mystery- … ton-leroux
It’s a marvelous tale, but I’d have probably never heard about the book or its author if it weren’t so easily available in the public domain. It may even real more of his tales. He won’t get a penny, but then he died in 1927, so what does it matter? The public domain has given him a reading legacy.
Finally, keep in mind that fair use law is extraordinarily complex and deliberately intended to require the weighing of multiple factors. Years ago, the Tolkien estate challenged my day-by-day The Lord of Rings chronology, arguing quite correctly that my book not only gives away the plot, it includes every plot element in the book. I won in Seattle federal court thanks to my fair use arguments. If you’d like to read those arguments, I repackaged them as the book’s last chapter when it was published.
They won’t help with those song lyrics though. Like I said, every fair use dispute is different.
–Michael W. Perry, author of Untangling Tolkien