2017/05/31: The songs that reached the top 10 were, on average, more repetitive than the rest in every year from 1960 to 2015!
Who's responsible for this madness?
Let's look at the average repetitiveness of some prolific artists in the dataset (those that have at least 15 charting songs as solo artists).
Genre does seem like a differentiating factor here. In the 00's, our artists actually separate pretty cleanly into two clusters, with country music and hip-hop (and whatever John Mayer does) on the left, and pop and rock on the right.
The variation between artists is considerable. The Backstreet Boys have an average compression ratio of 60%, to Brad Paisley's 38%. In other words, if we asked the Backstreet Boys and Brad Paisley to each write a 400 word song, and compressed them both, we'd expect Brad's compressed song to be 50% bigger than BSB's.
Let's zoom in on a specific artist, say Gwen Stefani. Each circle below represents a song in her discography. The background blob is the histogram of all songs in the dataset (the same one as before, but mirrored).