Sir Simon Rattle and the London Symphony Orchestra began the year with a world première. Unsuk Chin’s Second Violin Concerto opened with the soloist, Leonidas Kavakos, completely alone in front of a silent orchestra, playing phrases that rocked back and forth until, suddenly, they were striking sparks. As well they might; Kavakos, after all, is the reason that the concerto exists — the violinist whose ‘burningly intense’ (the composer’s words) artistry has prompted Chin to break her self-imposed rule of writing only one concerto for any given instrument.