Then his mood changed abruptly and he was talking happily about a movie he’d seen on HBO. Then his phone was beeping with a text message from a friend. He had to go, bye, Mom, love you, see you soon.

Click.

The millisecond of spontaneous “love you” made the whole negotiation worth it.

She hung up and glanced at Rhyme. “Kids?”

“Me? No. I don’t know that they’d be my strong suit.”

“They’re nobody’s strong suit until you have them.”

He was looking at her ubiquitous iPod earphones, which dangled around her neck like a stethoscope on a doctor. “You like music, I gather. . . . How’s that for a clever deduction?”

Dance said, “It’s my hobby.”

“Really? You play?”

“I sing some. I used to be a folkie. But now, if I take time off, I throw the kids and the dogs into the back of a camper and go track down songs.”

Rhyme frowned. “I’ve heard of that. It’s called—”

“Song catching is the popular phrase.”

“Sure. That’s it.”

This was a passion for Kathryn Dance. She was part of a long tradition of folklorists, people who would travel to out-of-the-way places to field-record traditional music. Alan Lomax was perhaps the most famous of these, hiking throughout the U.S. and Europe to capture old-time songs. Dance went to the East Coast from time to time but those tunes had been well documented, so most of her recent trips were to inner cities, Nova Scotia, Western Canada, the bayou and places with large Latino populations, like Southern and Central California. She’d record and catalog the songs.

She told this to Rhyme and explained too about a website she and a friend maintained with information on the musicians, the songs and the music itself. They helped the musicians copyright their original songs and distributed to them any fees listeners paid for downloads of the music. Several musicians had been contacted by record companies, which had bought their music for sound tracks of independent films.

Kathryn Dance didn’t tell Rhyme, though, that there was more to her relationship with music.

Dance often found herself overloaded. To do her job well, she needed to hard-wire herself to the witnesses and criminals she interviewed. Sitting three feet from a psychotic killer, jousting with him for hours or days or weeks, was an exhilarating process, but exhausting and debilitating too. Dance was so empathic and so closely connected to her subjects that she felt their emotions long after the sessions ended. She heard their voices in her mind, endlessly looping through her thoughts.

Sí, sí, okay, sí, I kill her. I cut her throat. . . . Well, her son too, that boy. He there. He see me. I have to kill him, I mean, who wouldn’t? But she deserve it, the way she look at me. It no my fault. Can I have that cigarette you talking about?

The music was a miracle cure. If Kathryn Dance was listening to Sonny Terry and Brownie McGhee or U2 or Dylan or David Byrne, she wasn’t replaying the memory of an indignant Carlos Allende complaining that the victim’s engagement ring cut his palm while he was slitting her throat.