In Lead Sister (Rowman & Littlefield, Oct.), O’Brien profiles trailblazing musician Karen Carpenter.

Was there an insight that surprised you most as you researched the biography?
I wanted to write this book partly because I felt that for so long Karen Carpenter had been framed as a victim in a tragic story—and it is tragic, but at the same time, this woman was literally at the top of the music industry throughout the 1970s, which was a huge feat. As I conducted interviews, I got a distinct picture of a very driven young woman who was extremely sure about her art and her singing and drumming. She was also quite a driving force in the musical duo [with brother Richard Carpenter]. There was a notion that he was steering the ship, but the more I looked into it, it became clear that she was really determining direction in lots of ways. She was the boss backstage, directing the band and putting people through their paces.

How was Carpenter’s eating disorder viewed in the 1970s and ’80s?
I think what really struck me as I was talking to different people from Carpenter’s life—particularly to Rebecca Segal, the duo’s tour manager—was that Karen’s eating disorder was an open secret. Rebecca was talking about the sense of helplessness that everyone around Karen felt. They could see that she wasn’t eating, but at that time, there was no language for anorexia.

In many ways, Karen’s story was the beginning of a really big, important conversation about eating disorders. At the time, I think Karen must have been very isolated and lonely with her disorder—she was really grappling with it on her own, which must have been terrifying.

What was the process of trying to get into Carpenter’s head as you wrote?
My sense of her came through strongly when I visited L.A. to do what is called psychogeography, in which you absorb the atmosphere of places to understand how someone there felt—in this case, I visited where Carpenter lived and worked. I went to her old studio—formerly A&M Studios, now the Henson Recording Studios. Those studios are fascinating because they’re almost unchanged from the 1970s and you feel like you’re back in time. They let me spend some time there, just absorbing the atmosphere—especially in Studio B, which is said to be the “Karen” studio, where they’ve got a big crystal heart on the wall, and when the engineers lock up, they say good night to Karen. I think that partly, the studio was her happy place—where she really felt at home, and where the anxious, nervous energy that fueled her released, and she could just be herself.