WASHINGTON — According to a new study from researchers at the Spanish National Research Council, the familiar complaint that contemporary popular music has grown loud, predictable and simpler than ever may be exactly right. While we often cast a skeptical eye toward quantitative studies of music like this one, a closer examination of the paper reveals that even for skeptics the analysis may have a point — even if the portrait it paints is incomplete.

Here's how the study worked. The analysts ran 464,411 recordings from all genres of popular music from the period of 1955-2010 (called the "Million Song Dataset") through a complex set of algorithms to analyze three metrics: harmonic complexity, timbral diversity and loudness. The results indicated that, on the whole, popular music over the past half-century has become blander and louder than it used to be.

To understand these findings, it's worth briefly delving into the terms in question. Most people are familiar with the idea that popular songs are constructed chiefly of a melody (usually the lead vocal line or tune) and supporting harmonies called chords (rhythm is the other chief component, but more on that later). The study found that, since the '50s, there has been a decrease not only in the diversity of chords in a given song, but also in the number of novel transitions, or musical pathways, between them. In other words, while it's true that pop songs have always been far more limited in their harmonic vocabularies than, say, a classical symphony, past decades saw more inventive ways of linking their harmonies together than we hear now. It's the difference between Carly Rae Jepsen's "Call Me Maybe" (2012), which contains four simple chords presented one after another almost as blocks, and Alex North's "Unchained Melody" (1955), which, though also relatively harmonically simple (it employs about six or seven chords, depending on the version), transitions smoothly from chord to chord due to more subtle orchestration.

The research group also discovered that "timbres" — or the distinct "textures" produced by different instruments playing the same note — have gotten more homogenous over time. To be clear, this is not to say that musicians are using fewer or different instruments now than before; rather, since 1955, pop has tended to use a smaller and more homogenous palette of "tone colors" at a given time.

The final finding — that music recordings have grown louder and louder over time — will come as no surprise to those who've been following the so-called "Loudness Wars, " but this seems to represent the first data-driven proof of the phenomenon. As producers compete for the attention of radio listeners to make their artist's recordings a hit, they've been gradually ratcheting up the inherent volume of the tracks at the cost of sound quality and dynamic richness. (You can hear what this sounds like on YouTube.)

So all this study's conclusions seem plausible, but does it really mean that our pop is dumber than before? To answer that, it's important to also ask what the researchers didn't study. For instance, though "Call Me Maybe" is made from a rather blunt and familiar set of four chords, the infectiousness of the song, at least for this listener, is located in both the playful rhythmic friction between the vocals and instruments — rhythm, crucially, was not taken into account in this study — as well as the cappuccino-cozy, almost country quality of Jepsen's voice. (Note how it glides and sometimes endearingly stumbles over her love-drunk lyrics.)

Indeed, so much musical interest in this hip-pop and dance-pop moment of recent years derives from the pervasive four-on-the-floor dance beat — and, crucially, well-crafted rhythmic dissensions from it. ("Unchained Melody," while a gorgeous song, isn't known for its beat.) As tempting as it may be to try to decode the "musical discourse," as these researchers called it, there are certain aspects of music — ineffable and otherwise — that will always elude your dataset.