Using 50 years worth of music and led by artificial intelligence specialist Joan Serra at the Spanish National Research Council, researchers have determined that the more modern the song, the more they 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.