Heath had been doing this long enough to recognize talent. Most people who busked in parks and tubes and the like weren't all that good, really, he just liked them for the passion they brought to it.
But she was good, too, which was a nice turn to things. He was smiling by the time she finished - completely oblivious to the looks he was getting from a group of girls near the fountain. He'd usually have noticed and left already, but he'd been too engrossed in the song.