A team led by artificial intelligence specialist Joan Serra at the Spanish National Research Council ran music from the last 50 years through some complex algorithms and found that pop songs have become intrinsically louder and more bland in terms of the chords, melodies and types of sound used.“We found evidence of a progressive homogenization of the musical discourse,” Serra told Reuters. “In particular, we obtained numerical indicators that the diversity of transitions between note combinations - roughly speaking chords plus melodies - has consistently diminished in the last 50 years.”
They also found the so-called timbre palette has become poorer. The same note played at the same volume on, say, a piano and a guitar is said to have a different timbre, so the researchers found modern pop has a more limited variety of sounds.