The scepticism about modern music shared by many middle-aged fans has been vindicated by a study of half a century’s worth of pop music, which found that today’s hits really do all sound the same. (I’ve been saying this for years: if you look at the Top Ten charts from the 1960s or 1970s you find much more variety than you do today, when the charts are relentlessly Katy, Gaga, Adele, Rihanna.) Parents who find their children’s thumping headphones too much to bear will also be comforted to know that it isn’t just the effect of age: modern songs have also grown progressively louder over the past 50 years. The study, by Spanish researchers, analyzed an archive known as the Million Song Dataset to discover how the course of music changed between 1955 and 2010. While loudness has steadily increased since the 1950s, the team found that the variety of chords, melodies and types of sound being used by musicians has become ever smaller.