Dawinsor, thanks for the info!
I should have been more clear. The quotes I plan to use are from other books, not from people I've spoken to. In some cases, I want to use several fairly long quotes from a single book, so I expect I'll need permission.
After posting on this thread, I realize that songs lyrics are an issue in my own book. I'm writing an unauthorized biography of Michael Jackson. There are a couple of places where I want to discuss his approach to lyrics, and I'm not sure I can do that without quoting at least very short parts of the lyrics. For example, Michael Jackson often deliberately mispronounced words because he felt the "new" pronunciation did a better job of conveying the emotions of the song. I want to give an example of this: he often pronounced the phrase "come on" as "shamone." I think it's probably OK to quote the phrase "come on," because it's both very short and a very common phrase, so it probably not protected by copyright even when used in a song.
A more difficult problem occurs with his use of lyrics as a form of percussion. For example, his song "Smooth Criminal" uses a staccato repetition of the phrase "Annie, are you OK?" over and over again. I have seen reviewers mention that specific phrase ("Annie, are you OK?") in published reviews of this song. However, I think reviewers may be more entitled to quote from a work they're reviewing than biographers are.
So, instead of the whole phrase "Annie, are you OK?" I'm considering saying something like, "Much of the lyrics in 'Smooth Criminal' consist of multiple repetitions of the name 'Annie' and the phrase 'Are you OK?'"
By doing this, the longest phrase I'll be quoting is "Are you OK?" Again, that's a short phrase and is very common, so I think it's not protected by copyright even when used in a song.
What do people here think?