Calvin grinned widely, able to see the silly grin potential that Emily was holding back and responding to that. It faded a little into a more thoughtful expression as he listened to what she was saying, but he didn't say anything more until after she'd finished singing her song.
"If he hurts you I'll hurt him," he muttered, loud enough that she could hear but soft enough that she could ignore it if she wanted. And, looking up, he added conversationally, still aiming at convincing her, "You can't really get away from risk, but I don't think you should be nervous about that song, it's haunting, even unfinished. But writing songs is all about being exposed, isn't it?" He paused a moment, then asked, looking at her directly, "Would you really be happier silent?"