In my view, pop music goes way beyond the conventional idea of a "song" (melody plus lyrics). Rhythm is vital, especially if you consider the development of American music over the past 140 years or so. Relatively simplistic tunes were turned into instrumental hits by iconic recordings. "Hooks" and "drops" are important elements of pop hits.

Being somewhat of an old timer, I continue to be amazed by how the very idea of what constitutes a pop hit changes over time. As a kid, I could never have anticipated hip hop.

Rhythm and feel are massively underappreciated, especially in traditional music theory.

The difference between a perfect groove and crap rhythm programming is literally ms, and the difference between talent and mediocrity is often down to being able to feel those tiny timing offsets.

It's also a central feature of classical performances. Timing variations are controlled with extreme precision, and can make or break an interpretation.

Indeed, "music theory" is largely melodic and harmonic theory, and the study of the study of larger structures such as the sonata form. Rhythm is left up to the personal taste of the composer and performer.

Notice that the actual scientific article [1] doesn't make any considerations about quality.

It only takes objective measures and observes that they've been following the same patterns (probability distributions) over the last 50 years, just with variations on the distributions' parameters. Furthermore, they observe that the parameter changes over time are always to lower-variance versions for these distributions.

Finally, they argue that you could take a generic pop song from 50 years ago, modify it according to the current changes in parameters (adjust the harmonic progressions to the currently fashionable ones, change the instrumentation, and increase the average loudness) and it should sound like a modern generic pop song.

More importantly, they make no claims whatsoever regarding the quality of individual songs. In fact, they never study nor reflect on individual songs.

The original article's TLDR is: Music from the last 50-60 years has been using the same basic principles, and variance in timbre, pitch and loudness is decreasing over time between the mass of pop songs.

[1] https://www.nature.com/articles/srep00521

Lyrics seem to be getting more repetitive as well: https://pudding.cool/2017/05/song-repetition/

Is this a terrible thing? Why does content have to be original and unique to be good? Why can't content be similar, or even referential?

One of most notable example of a non-unique song, Aretha Franklin's Respect, is actually a cover, and the parts which are original to that particular rendition are quite repetitive. If we were to take out covers and samples from the body of music, we wouldn't have very much left.

From an entertainment perspective I might agree. However, music is a cultural expression (or should be). We should have stories to tell each other. Emotions more complicated than maudlin songs lamenting a lost love. Take away the content and music becomes a pretty screensaver. Interesting at first but non-engaging and without a message.

I do think pitch content is a useful metric. A lot of popular songs reuse a handful of common chord progressions. While the key and timbre may change from song to song, the tension and resolution of the chord changes, which can often be heard to have a certain feeling or emotional content in Western music, remains the same.

For me, it is the measure of a talented and mature musician is: one who knows how to leave space in a song, giving the melody room to breathe and the listener time to reflect and anticipate.

Blues and Jazz artists inherently understand this. It is essential in classical. However, modern pop music, which has become saturated with hip-hop/rap influence, is going the opposite direction, filling every possible space with noise. The loudness war is only one facet of this.

Well lyrics and instruments certainly haven't gotten better. Drum machines and electronic effects have taken over for instruments and lyrics are about as shallow as they can be right now.

Lyrics for popular music were always shallow. It's no worse today.

Well today's lyrics are worse in at least one objective way: number of unique words.

In the "good old days" you could at least count on a verse, chorus, different verse, chorus, etc. structure. Then at some point they were doing "chorus, chorus, chorus, bridge, chorus...". Soon we'll be lucky to get more than a repeated sentence fragment.

Case in point: https://www.google.ca/search?q=turn+down+for+what+lyrics

Or this gem: https://www.google.ca/search?q=watch+me+whip+lyrics

The Beatles' "I want you (she's so heavy)" from Abbey Road has probably fewer unique words than those, yet I think it's a pretty good song.

A better example of a pop song might be Twist and Shout; not much variety there either.

Depends on what you define as "the good old days."

Latin church hymns, for example, largely use the same corpus of Latin for lyrics, but no one is about to accuse Mozart or Beethoven of a crisis of originality in lyrics.

Case in point: https://www.cpdl.org/wiki/images/3/32/Mozart_427_Great_Mass_...

>Well today's lyrics are worse in at least one objective way: number of unique words.

That's not a good metric.

Right. I occasionally hear local word-rich rap and it is low quality lyrics overall. In particular, it’s like they explain every line with ten more lines, as if their listener was an idiot who cannot read between these.

If I looked for a good metric, I would probably take min(word per meaning and touch), but that would raise a question on what ‘meaning and touch’ is. Nonetheless, good lyrics always seem to be un/under-spoken or sharp cut.

Yes! In poetry, William Carlos Williams is a great example. In music, Lou Reed and Randy Newman are good examples.

Ok fine, objectively there's less lyric content and more repetition; and subjectively the lyrics aren't exactly getting more insightful or laconic to compensate.

I'd say that writing in music tends to be pretty terrible across the board - with a few exceptions during each period.

Lyrics are guaranteed to improve over the very long term, as language change gradually renders old lyrics literally unintelligible.

There may be an objective sense in which a song from thousands of years ago has better lyrics than one from today, but nobody can perceive it through the language barrier.

Electronic production has meant that music has gotten more versatile than ever

Music that combines real instruments and electronic instruments can produce a much wider variety of sounds than either type alone.

And electronic effects are hardly a new thing - they've been around since the mid 80s.