The Invisible Thing That (Almost) All Your Music Has in Common

Mar 20, 2015

A saxophonist plays on the street during SXSW.
Credit Marshall Tidrick/KUT

At South by Southwest Music you can hear everything from metal and rock to hip hop and electronic music.

Dozens of genres – but for the most part, they all have one very basic thing in common.

If you’re a musician, it might sound familiar to you:
The musical note A, above middle C, equals 440 hertz.

It’s the basis of virtually every piece of music you’ll hear today. And probably every piece of music you have ever heard, with a few exceptions.

It’s called reference pitch or concert pitch. It’s the note that every other note is based on.

Take a listen:

Every instrument in Western music – more or less – is tuned to this standard.

But it was not always this way. A was not always A. Or at least not the A that we know.

“Going back thousands of years, when music in the West was mostly a vocal tradition, it didn’t matter so much what reference pitch was,” says Andrew Dell’Antonio, who teaches music history at the Butler School of Music at the University of Texas at Austin. He says it didn’t matter in vocal music because “a bunch of singers would decide ‘ok, we’re going to start with this and it works and off we go.’”

It wasn’t until instruments with fixed pitches came along that musicians needed standards.

At first, they tried to standardize pitches on church organs, but you could still go from one city to another and find a completely different tuning. Then, about 200 years ago, things reached a breaking point.

“As more and more instrumental music became the standard, pitch rose substantially from the later 1700s to the early to mid-1800s,” says Dell’Antonio. Instrumentalists’ pitch rose higher and higher, chasing what they call “brightness.”

But, the singers accompanying those musicians were having a hard time.

“So singers, from fairly early on were saying ‘wait a second, as you tune further up, our voices begin to strain,’” says Dell’Antonio.

So they decided to do something about it.

“These singers go to the Parisian Conservatory and they say ‘look, what we need from you all is to kick these instrumentalists back into their place,'” Dell’Antonio says. “You know, to say we can’t keep rising and rising in pitch. Let’s establish a standard for everybody to go by.”

So the French establish a standard reference pitch of A=435 hz.

Over in England, they had different ideas. They went with a standard of 439 hz.

By the early 1900s, there still wasn’t any consistent standard pitch in all the different countries. Then, by 1939, everyone in Europe and North America got together to finally approve a standard that they could all agree on. Remember there’s the French standard at 435 and the British at 439. Now, everyone felt like they can get behind 439, says Dell’Antonio, “but 439 is a prime number. And if you’re trying to generate it electronically, it’s a pain in the patoot.”

So, they went with 440, “because it was close enough.”

That settled it, an international standard of A equals 440 hertz. That’s the way it’s been ever since. (Though some orchestras do tune slightly higher than 440 hz).

"I guess in a parallel universe it might converge to another number, but we converged to 440 hertz,” says Trevor Cox, an acoustical engineering professor at Salford University in the UK.

But there are folks out there who wonder: Is 440 the best frequency?

There are a bunch of them out there saying the standard should be 432 hz.

Search YouTube for 432 hertz, and you’ll likely come across something like this:

Some say tuning to 432 hz sounds richer or warmer. But there’s also some more out-there ideas.

“It’s a mixture of you know, ‘we vibrate, our DNA vibrates, and therefore, this is the frequency of universe’ kind of stuff,” says Cox.

There are some Nazi and Illuminati conspiracies in there, too.

But let's compare the two. Here’s two versions of Sade’s Cherish the Day – one at the original 440 hz, the other retuned to 432 hz.

Cox was curious: Is there something about A=432 hz that resonates with us? So he tested it out. He took 10 pieces of music and retuned them all to various tunings, some higher than 440, some lower.

He got a bunch of people to go to a website, listen and say which ones they preferred.

His results?

"If you went up in pitch from 440 hertz, then the music sounded worse,” says Cox. “If you went down in pitch, it didn’t sound any different in terms of preference.”

But “440 hertz was still the one that was preferred the most.”

People liked the music tuned to 440 best. Now, it could be that that’s just what people are used to hearing. But while you might hear something and say ‘yes, I like that’ or ‘no, I don’t,’ there’s also the subconscious aspect of music, right?

So could a difference of 8 hz change how we experience music in ways we don’t even know?

“I am certain that even one hertz would change subconsciously how we experience music,” says Dell’Antonio from UT-Austin. “People have talked for a long time about the healing power of sound. There are lots of world traditions that rely on bowls and other sound-producing devices to affect the body subconsciously. So I don’t want to say ‘no, that’s not a thing at all. It can’t be a thing.’ It’s just hard to know exactly how that thing happens and whether the way for that thing to happen most effectively is to take your favorite song and crank it down 8 hertz.”

Trevor Cox isn’t so sure.

“If there was a subconscious difference – let’s say 432 hertz is better for our health. Let’s suppose that is true,” says Cox. “Then when I do a preference test, you would expect 432 hertz to be preferred. Because for evolutionary reasons, we ought to develop a like for stuff that is good for us. We see that all the time in evolutionary biology. So really if 432 hertz was really doing something subconscious, I’d also expect it to emerge in preference scores, as well.”

And yet, it doesn’t – at least in the limited study that’s been done on the idea.

Still, the idea isn’t going away, if you believe YouTube. You can even find smartphone apps that retune your music to 432 hz. And of course, there are other musical traditions that don’t use A=440.

But 75 years since the standard was established, for the most part, the 440 hz standard doesn’t appear to be in any danger.