He looks a little dubious at her assertion that she's fine, feigned concern still lingering on his face, but he nods, like, okay, he'll take her word for it.

"It's just music, you know? It's like..." And now there's a twist of a smile, his insincerity tainted with something genuine, some lingering remnants of his humanity. "When everything comes together, like the crowd and the music, and all those emotions running wild? I dunno. It's totally transcendent." He shrugs, a little bit wistful. "I guess it can feel like magic."

That crack in Jeff's mask, that slip of humanity and honesty, might end up giving the game away. Sure, he likes to think it'll reinforce his feigned innocence, blending truth with lies like that, but it could screw him here. Now there's something real to latch onto, in contrast with the lies.