Originally Posted by MusicNewb1981

Well, the Smithsonian article linked to a Scientific America article that goes into greater detail about the methodology of the research. According to the Scientific America article,

1) The database is the Million Song Database but of the Million songs featured only 464,411 are between 1955 - 2010 of which were used for the study.

2) So the study covers the period between 1955 - 2010 and doesn't mention any representative sample issues. The sample size appears sufficient.

If you get past that methodology, the study concludes:

1) Timbre quality (defined by the study not as a laymen's term definition of timbre but as sound color, texture, or tone quality. So, essentially, the musical dynamics of a song) has declined since 1960 which, according to the researchers concludes, less diversity in instrumentation (instruments used if at all) and recording technique (production value)

2) Pitch content (defined as harmony, melody, chord progression choice) has also diminished. The study conclude the same progressions etc...are being used as 1960 but with stricter syntax. This means it's a very rigid application of old structures.

3) Songs are louder (loudness not in volume but in production recording) the study concludes there is much less dynamic range, meaning background parts exist less if it all.

So, in laymen terms: songs are statistically shown to decline in instrumentation, production value, creativity of form, rigidity to a few old progressions or forms, and songs cover up any detail with loudness.

That is me summarizing the study in laymen terms. Others can summarize it differently but go to the Smithsonian and Scientific America article for details.

Again, I think what the study concludes is pretty accurate to my experience of recent music. How many Youtube videos are there about, "the three chords of 100 popular songs," or other videos. As far as what I hear in pop music, there are no instruments but a drum beat and some synthesized bass. The music doesn't have a background part, or a subtle theme or counter-point. So, I don't find the study inaccurate. The only thing novel about it, is that it quantified it.