PARIS: Your mother was right: Pop music has become louder and less original over the years.

At least, this is the conclusion of a computer analysis of nearly half-a-million songs recorded between 1955 and 2010 and reported in Nature Scientific Reports Thursday.

"We have been able to show how the global loudness level of music recordings has consistently increased over the years," study author Joan Serra of the Spanish National Research Council said in an email exchange.

Similarly, the team found the diversity of chords and melodies has "consistently diminished in the last 50 years".

"This yields a clear recipe for contemporising old songs: using more common chord changes, changing the song's instrumentation, and record it louder," said Serra.

The study spanned a variety of genres, including rock, pop, hip hop, metal and electronic.

It mentioned no songs by name, simply analysing the music in algorithms of numbers and symbols in search of patterns.

"Much of the gathered evidence points towards an important degree of conventionalism, in the sense of blockage or no-evolution, in the creation and production of contemporary Western popular music," said the study.