He stopped. The orchestra stumbled to silence. For a moment, no one clapped, because no one knew whether they were witnessing a joke or the collapse of something they had paid to believe.
"Dry throat," Chase said, laughing with visible effort. "It happens. That's why we protect our voices on long tours."
"You didn't hit it," Zara said, not cruelly, but with the bewildered accuracy of a child describing a broken light. Her mouth moved before she could consider the effect of the words. "That wasn't the note from the album."
Chase turned toward her. "What did you say?"
"I listened to the recording a lot because I wanted to learn it," she said. "On the album it's a C in the sixth octave, and the high part sounds different from your live voice. I heard the change this afternoon when the track came in."
He stared at her, then looked toward the audience and raised both hands in a theatrical expression of patience. "Ladies and gentlemen, apparently we have a tiny music professor with us tonight." Some people laughed, but many were now recording the exchange rather than applauding it. The laughter faded as Zara kept speaking.
"I can identify notes when I hear them," she explained. "Ms. Johnson tested me. The recorded C6 is about one thousand forty-six and a half hertz, and what you reached a moment ago sounded closer to A-sharp five. That's about nine hundred thirty-two hertz. I know voices can be tired, but the recording was exact every time."
She was not trying to calculate a spectrum analyzer's report from memory. She had learned the pitch frequencies while practicing with a tuning application, and she knew the note labels by ear. The exact numbers were supporting details, not magic evidence of who had sung on a record. What mattered was the difference she had heard between the strained live attempt and the bright recorded phrase that entered every performance unchanged.
"You're a child," Chase said. His voice was low now, stripped of the public warmth that had filled the theater earlier. "You do not understand the first thing about professional recording."
"Maybe not everything," Zara admitted. "But I saw the program. It says Sophia Mitchell did additional vocals. Is that her singing the note?"
The audience shifted visibly. Aaron took off his headphones. Somewhere near the press seats, a reporter began typing so quickly that Zara could hear the faint tapping through a gap in the music.
"Enough," Chase said. "I tried to give you a beautiful moment, and you're making accusations you can't possibly support."
"Then tell me who sang it," Zara replied. She looked at him directly for the first time since he had called her down from the risers. "If it's you, I will say I'm wrong. I don't want to be mean to anybody. I just want to know."
Chase reached for her forearm, apparently intending to steer her back toward the choir. Ms. Johnson was halfway onto the stage before he touched her, and the orchestra's conductor set down his baton. Chase released her when he saw the cameras move closer. The first person to speak was not Ms. Johnson, however, but Aaron Fields.