Overtones is a column that examines how certain sounds linger in our minds and lives.

Can music help you? Does it hurt you? People care deeply about these questions. Until recently, however, I did not. I live with music—it occupies my free time and my work time—and yet, I've almost never thought about this.

On the rare occasions when I have, though, it's always with bone-deep certainty: Of course music can't hurt you. Like anyone who hasn't thought hard enough about something, I took all the evidence that I needed for this from my own life. I grew up listening to tapes of Slayer, Metallica, Megadeth, Ice-T, Ice Cube, N.W.A.—when I was nine years old, my favorite song included the line "most motherfuckers don't give a damn." My mother certainly didn't approve, but she also didn't yank away a tape I had already memorized. We talked about what was wrong with calling someone a "mother effer," why it was an ugly word. The tape stayed with me, and the conversation did too. And now, I’m a generally respectable and decent adult human (or at least not visibly warped).

The reason I'm currently probing these questions is predictable: I am the father of a 14-month-old girl, and becoming a parent re-sensitizes you to your environment in fresh ways. Some are helpful, but many—most—are mindless, reflexive, and fearful, requiring occasional correction from the pre-parent brain. The world didn't grow more dangerous, in other words, I just momentarily grew more fearful of it.

Anxiety has an ability to draw the ear towards half-truths—studies on rumors, urban legends, and conspiracy theories have shown that the more anxious the disposition, the more susceptible a person becomes to hearsay. And I sense free-floating anxiety at play whenever a public figure worries about what music "does" to us, whether we can figure out how it "works" in our brain. The infamous "Mozart effect," which still spurs sales of classical music for babies in boutique toy shops, is a perfect illustration. The actual study, and the way it became willfully, eagerly misinterpreted, is a little opera about science and magical thinking.

The actual Mozart effect was so modest that it's difficult to believe it even became controversial—in a 1993 study published in Nature, Frances Rauscher demonstrated that college students who listened to Mozart for 10 minutes briefly scored higher on spatial reasoning tasks. The effect wore off soon after, and no other areas of test-taking improved. When the study was first published, the interest was modest—Adrian Bangerter and Chip Heath, who tracked the Mozart effect's journey through lay culture in a 2004 study published by the British Psychological Society, found that in the year the study appeared, it was only cited seven times. Further studies attempting to replicate the effect had mixed results, and by 1999, a review of these studies concluded that the effect, if it existed, was negligible.

However, a mysterious ball had been set rolling in the culture, one that would roll far, far away from science. In 1997, a music critic, author, and entrepreneur named Don Campbell published The Mozart Effect for Children: Awakening Your Child's Mind, Health, and Creativity With Music. It was an interesting title—the original study was not done on children—and it appeared just as the study's initial results were proving most difficult to replicate.

But it didn't matter. Campbell's book soon built a massive, and massively profitable, cottage industry that you can still find the vestiges of today: Even in baby books purporting to rely entirely on proven studies and hard science, like Baby 411: Clear Answers & Smart Advice for Your Baby's First Year, you can find helpful advice to play classical music for your child's developing brain. In 1998, the state of Georgia passed a law to distribute classical CDs to new mothers; that same year, Florida passed a law requiring state-funded daycare centers to play classical music for their children every day. One year later, Houston began playing classical music to its prison inmates, and Korean researchers played Mozart for germinating roses.

The irony and astonishment of all this furious activity, of course, is that no one actually said anything about babies (or roses) in the first place. This willful misunderstanding is what Bangerter and Heath term a "scientific legend": a widespread belief derived from science that differs widely from the beliefs of actual scientists. The Mozart effect was fanuted, as French Montana might say, from a temporary effect on adults to a permanent effect in infants, via the transitive property of people's wishful thinking. The notion tapped directly into our collective queasiness about what Jerome Kagan, in his 2000 book Three Seductive Ideas, called "infant determinism," or the belief that the first two years of a child's life maps their subsequent path. In this way, Mozart became just the first of a child's many test tutors.

As a person who has gazed, helplessly, at his mute baby's head, wondering frantically what I already wasn't doing to help develop the brain inside it, I understand the underlying fear: It is a panic I can practically taste. I have played my baby Debussy (string quartet, third movement), along with Schubert, Bach and, yes, Mozart. I don't think any of it made her smarter—most times, she never even looked up—but I did it anyway, because it provided a slight easing in my chest. For new parents, at least, the Mozart effect is very real.

I sometimes wonder about the racial coding of all this: I'd like to see a serious study on whether playing Queens rapper Cormega for one-year-olds enhances their understanding of the rhythms and cadence of human speech. As for studies linking rap music or heavy metal to violence—those, thankfully, seem to have receded somewhat. The last widely reported study was in 2006, when researchers attempted to find the link between hip-hop listening and alcohol abuse. Media concern (or concern-trolling) about the societal effects of rap violence continues unabated, but the science has, for the most part, piped down, for the same reason the Mozart effect studies tapered off. The research showing that violent music makes you violent is about as unreliable as the research proving that Mozart makes you smarter.

The truth is, no one knows what music does in the brain. We know that musical training has observable benefits, just as we know that listening to music can have a powerful effect on people with certain cognitive disorders—aphasics, for example, or people whose short-term memory has been impaired. But when it comes to tracing the penny of music as it rolls through the vaults of an average brain, we are still basically helpless.

Partly, this is because music activates so many disparate regions at once. But more broadly, it's because music itself is a notoriously leaky container for agendas or specific ideas. Melodies and rhythms, once free of their creators, make their own place in the world, serenely unconcerned with the aims of who sent them there. Utopian music can be warped to pernicious ends, as it was in Hitler's Germany, just as violent, antisocial music can serve as a beacon of hope and consolation. Violence itself, like joy or beauty or ugliness, is entirely in the ear of the beholder: I find the compression of pop records, which transforms every moment into one long scream, to be more violent than, say, a well-recorded metal album, with a sense of space and distance between instruments in the mix, though I wholeheartedly accept that this is an aberrant view caused by the idiosyncrasies of my chosen profession.

Circumstances around music change how it works, too. If there is no sexual chemistry between two people, putting on D'Angelo's Brown Sugar while they are alone in a room will do absolutely nothing to change that, and they will stare at each other awkwardly. If two people have a latent desire to tear each other's clothes off, the same album will probably encourage them to do that. If a room is full of tension and frustration and simmering grudges, playing the Lox's "Wild Out" could very well lead to someone breaking a bottle over someone else's head. If you play it in a library on a Tuesday afternoon, it likely won't have that effect. We help and hurt each other all the time. Occasionally, music is playing.