Maybe he should have chosen a different song, but after his meeting with James he'd been plagued by bitterness that he had to externalize somehow. Knowing he was making Lotte nervous filled him with a sick sort of satisfaction mingled with sharp guilt - it was painful, almost physically so, but that was fine by him. Pain had stopped being something to fear a long time ago and now acted as a coping mechanism. It was familiar, and familiar was safe.
Bran waited until she finished, his scowl becoming less pronounced as she continued. They needed to work on her confidence and on her fear - either she used it or tucked it away for another time, it couldn't be so close to the surface - but once she felt the emotion of the song, it became something wondrous. "Your voice is good, of that there is no doubt - but raw talent will only get you so far. You need to know how to use it, how to perfect it; which is what I'll help you with."
He paused, waiting a few moments before speaking again. "Your voice shook at the beginning - it was weak and audibly faltered. Can you tell me why?"