The National’s Aaron Dessner talked with Pitchfork about working on Taylor Swift’s latest album:

So when [Taylor] reached out, I had this large folder of ideas that were pretty well on their way. She was very clear that she didn’t want me to edit any of my ideas; she wanted to hear everything that was interesting to me at this moment, including really odd, experimental noise. So I made a folder of stuff, including some pretty out-there sketches. A few hours later, she sent “cardigan,” fully written in a voice memo. That’s when I realized that this was unusual—just the focus and clarity of her ideas. It was pretty astonishing. Over the next couple months, this would just happen; all of a sudden, I’d get a voice memo. And then another. Eventually, it was so inspiring that I wrote more ideas that were specifically in response to what she was writing.