The UK singles chart is 70 years old today and since Al Martino had the first No1 in 1952 hits have become shorter and slower, research shows.
The chart is more likely to have a diverse line-up of performers, but once-familiar elements, such as key changes and fades, have almost completely disappeared,
Experts analysed all of the 1,404 releases to reach No1, from Here In My Heart by Al Martino, to the latest, Anti-Hero by Taylor Swift.
