In his bedroom, my teenage son sits, ears encased in giant headphones linked to his phone, nodding to a beat no one else can hear.

There would be little point asking what he is listening to; he probably wouldn't be able to identify the track, picked out for him by a personalised algorithm gradually narrowing his taste down to a point halfway between overwrought emo singer-songwriters and spaced-out psychedelic hip-hop.

The Telegraph London