Richard Powers’s new novel, “Orfeo,” is about a retired composer who’s suspected of bioterrorism. But it’s really about music — what it means and what it can do. It’s impossible to read this exciting book without constantly setting it aside and tracking down the modern and contemporary pieces that Powers discusses so richly in these pages.

While getting ready for his book tour, Powers answered a few questions about the musical element of “Orfeo.”

As you wrote about these famous compositions, did you discover that they were different than you had remembered?

One of the great pleasures of any piece of music that has some heft to it is hearing how it continues to open up, even after many listenings. This doesn’t even require the passage of time. From one listen to the next, I sometimes wonder, “Was that in there before?” I don’t just mean hearing some new formal wrinkle or harmonic relationship: I mean noticing whole passages of actual notes! Of course, when you haven’t listened for a while, hearing a much-loved piece can be like looking at the world through the wrong end of the telescope: the thing is recognizable, intact, totally familiar, but completely changed.

Give me an example.

Take the Mahler songs I describe in the book: When I was young, I didn’t hear just how daring the harmonies are, or how entire passages teeter right on the brink of harmonic collapse. Or to give another example: I hadn’t really listened closely to Copland’s “Appalachian Spring” until I decided to use it in the early scene of young Peter on summer vacation at a lake in upstate New York. Although I thought I could sing the thing in my sleep, it was only then, at the age of 54, that I heard how Copland prepares all the changes leading up to his glorious climax in those first few quiet notes in the piece’s opening.

Did you listen to the music while actually writing – or was that too distracting?

The beauty of being a writer is that you can spend three or four years at a shot, living a vicarious life and indulging all the pleasures of a career road not taken. I love listening to music, and I will use it to delay writing, any chance I can take. In writing a book like “Orfeo,” an afternoon of listening wasn’t being delinquent — it was working!  I’m sure I listened to “The Quartet for the End of Time” 30 or 40 times while writing that section.

Has the golden age of experimentation passed?

The line between “classical” and the best of “popular” music is as thin now as it has been at any time since the 1960s. This is an exciting and eclectic time, adventurous and daring, with people trying things all over the aesthetic map. The biggest challenge for an ear that wants to listen closely and spend time discovering the delights of a piece of involved music is the sheer distraction of superabundance.

Your protagonist is so convinced of the power of music. Can it still wake us up, move us, make us feel alive?

The most gratifying thing about the release of “Orfeo,” by far, has been the number of people who have told me, with obvious excitement, about being wowed by a first-time listen to one or another of the pieces in the book. Steve Reich’s “Proverb,” in particular, seems to provoke the kind of response I had from a reader just this morning: “I didn’t realize music could be like that.”