"What is music? There’s no end to the parade of philosophers who have wondered about this, but most of us feel confident saying: ‘I know it when I hear it.’ Still, judgments of musicality are notoriously malleable. That new club tune, obnoxious at first, might become toe-tappingly likeable after a few hearings. Put the most music-apathetic individual in a household where someone is rehearsing for a contemporary music recital and they will leave whistling Ligeti. The simple act of repetition can serve as a quasi-magical agent of musicalisation. Instead of asking: ‘What is music?’ we might have an easier time asking: ‘What do we hear as music?’ And a remarkably large part of the answer appears to be: ‘I know it when I hear it again.’"