Really?
"Strikingly, they found 'the proportion of minor key songs doubled over five decades.... a general reduction in unambiguously happy-sounding recordings as well as an increase in recordings with ambiguous emotional states.'.... While conceding that pop fans may not be consciously aware of a preference for more complex music, the researchers speculate that 'musically untrained listeners may recognize quickly and explicitly that a contemporary fast-tempo, major mode song (such as Aqua’s Barbie Girl) has something amiss about it besides the lyrics.'.... This study suggests mass-appeal music is, on the whole, getting more nuanced and sophisticated."
Really?!
Not the impression I'm getting from listening to Top 40 stations here, that's for sure.