128: The Magic Number

In the new Zac Efron movie, We Are Your Friends, Zac’s superstar DJ character declares 128 beats per minute to be “the magic number” when it comes to making good dancefloor music. Sure enough, 128bpm does appear in pop with notable regularity – but is it really magic? We crack out our metronomes and get to the bottom of it.

Music is all about patterns. Melodic patterns, harmonic patterns, chord progressions, variations and repetitions. That’s essentially all it boils down to, and most of the patterns that underpin a lot of what the Western ear understands as music haven’t really changed as drastically as you might imagine in the last 400 years.

From baroque chamber music, through classical concertos and romantic sonatas, through ragtime, rock and roll and R’n’B, the fundamentals of music have stayed the same. We’ve been privy to this information for centuries now and all we’ve really been doing ever since is work our way through the many and varied combinations that those patterns allow for.

Why tell you any of this? Because you may have seen Zac Efron on the big screen recently, swanning about like he’s Simon fucking Rattle, talking as if he’s single-handedly unravelled the mysteries of music.

In a scene in his new movie, We Are Your Friends, (the scene which also acts as most of the trailer), the up-and-coming DJ (Efron) teaches us how to ‘rock a party’. He delivers a short, flashily-directed speech that has the exact same air about it that that Jennifer Aniston shampoo advert did – the one where she told us to concentrate for the ‘science bit’.

It is supremely irritating and smug, and he makes one rather definite claim in it. He says that, when it comes to music, 128 beats per minute is the magic number. Given that there is hundreds of years of well-established musical theory against which to test this claim, we thought we’d go ahead and try it out.

The Claim

First, let’s dissect what Zac Efron tells us – line by line.

“It’s the DJ’s job to get the crowd out of their heads and into their bodies.”

Hmmm. Possibly overselling the job a touch, but whatever. We’re not denying that DJing takes skill – and if Zac wants to take an explicitly physiological approach to this, then that’s fine by us. We’ll follow his lead.

“I like to start them off at about 125 beats per minute.”

Some songs that have a tempo of about 125bpm include Technotronic’s Pump Up The Jam, Jennifer Lopez’s Waiting For Tonight, Guns N’ Roses Sweet Child O’ Mine and Moby’s Why Does My Heart Feel So Bad?

All bona fide party starters.

“Once you’ve locked on to their heart rate…”

OK. Just hold it there a second, Zac. A healthy adult human should have a resting heart rate that sits somewhere between 60-100bpm. If you’re trying to start your party by beat-matching people’s hearts, you really want to be starting with songs like Complicated by Avril Lavigne (80bpm), Ms Jackson by Outkast (86bpm) or – if your audience looks like they may be just on the verge of prehypertension – Crazy In Love by Beyoncé (100bpm) or Rock Your Body by Justin Timberlake (104bpm).

125bpm is really rather fast – especially if you’re using the four-to-the-floor beat so prevalent in EDM music.

Anyway, sorry. You were saying?

“…that’s when you start bringing them up, song by song. 128 beats per minute.”

To give you some idea of the difference between 125bpm and 128bpm, perform this little experiment. Look at your watch. See the seconds tick by. Now try to double that. Click your fingers or tap your toe twice for every second. Tap, tap, tap, tap, tap, tap, tap, tap. Got it? OK. That’s roughly 125bpm.

Now, try it again. With your eye on the second hand, click your fingers or tap your toe twice for every tick. Tap, tap, tap, tap, tap, tap, tap, tap. Got it? Yeah, that’s also roughly 128bpm.

If you’d prefer to hear an actual metronome tapping it out, here’s 125bpm and here’s 128bpm.

Charitably, you could call this difference ‘subtle’ – but, really, speaking frankly, it’s small. Tiny. Almost imperceptible. It’s certainly not the sort of change that needs to be made song by song. You can easily beat-match a difference of 3bpm between two songs. You could probably even sneak it up within the space of a single song without anyone becoming confused or crying.

Still, there is a difference, and – just as a doctor would need to know the difference when a heart is beating at 125bpm and when it’s beating at 128bpm – a DJ needs to know the difference between the two different tempos too.

But we needn’t get too hung up on the specifics here, because the important line is this:

“128 beats per minute. That’s the magic number.”

Now, 128 is actually a very interesting number in music. Whether you could call it ‘magic’ is up for some debate, but there’s no coincidence here. Zac Efron didn’t just pluck this number from his firm, youthful arse. There is a reason he hit upon 128.

And the explanation for it involves technology, human biology and – joy of joys – some maths.

The Numbers

The reason 128 is such an interesting number in musical mathematics is because it marks the point where a few important staples of timing, structure and tempo all intersect. Four-four bars, eight-bar patterns, sixty-second minutes: they all align in perfect synchronicity at a tempo of 128bpm.

If you don’t know what any of that means, don’t worry – we’ll explain.


4 = Number Of Beats Per Bar

The vast majority of pop music is written in one very particular time signature: 4/4. Simply put, that means you count out the song in four-beat phrases. This is the absolute back-bone of pop music.

Occasionally you’ll get bands who choose not to write in 4/4 to show off a bit. Usually it’s prog rock bands like Pink Floyd and Yes who write in obscure time signatures (like 7/4 or 5/8) but even the most mainstream of bands like Simply Red have been known to chuck in the odd bar of 11/4 into their songs (specifically, in Simply Red’s case, their number one hit, Fairground).

Mostly though, it’s all in 4/4 – and you will be able to count along to almost every pop song with a simple ‘1, 2, 3, 4 / 1, 2, 3, 4’.

The speed of that count is what’s known as the tempo.

If you set your tempo at 128 beats per minute (bpm), you will find that you get through exactly 32 cycles of that ‘1, 2, 3, 4’ count every minute (128 = 32 x 4).

32 will be useful to us again shortly, so keep it in mind.


3 = Number Of Minutes Per Pop Song

Historically, pop songs never used to last any longer than three minutes. This wasn’t by design, so much as it was by necessity. Because of the physical and technical constraints of early vinyl, you could only fit a finite number of grooves on a record. If you wanted to maintain a decent sound quality, you only had enough space to accommodate about three minutes of music on each side (played at 78rpm – as early records were).

These formative constraints have had a long-lasting effect on the structure of pop music. For even though artists are no longer bound by them, and are now able to record and release singles which could be five minutes, ten minutes – half a goddamn hour, if the mood so took them – many pop hits still choose to stick close to the three-minute mark.

Why? Because that’s what we’re used to. That’s what we like, what we’ve grown to expect. We’ve become so used to hearing verse, chorus, verse, chorus, middle eight, chorus (all you’re feasibly able to fit inside of three minutes) that this is now the blueprint that most pop song writers work towards.

This figure of three minutes works in conjunction with 128bpm – because if a tempo of 128bpm means that you can fit 32 bars of 4/4 into one minute absolutely perfectly, it means you can fit 96 bars of 4/4 into three minutes absolutely perfectly.

And 96 is another interesting number.


96 = Number Of Bars Per Song

96 is incredibly versatile: not only divisible by itself and 1, but also by 2, 3, 4, 6, 8, 12, 16, 24, 32, 48.

These are all numbers that also crop up a lot in music. A lot of pop songs are made up of eight-bar, twelve-bar and sixteen-bar phrases, so using a 96-bar framework means that you can slot together a number of different combinations of these phrases.

None of this is to suggest that all pop songs have to be 96 bars long – a great many of them aren’t – but when you’re looking to precision-engineer a hit record, it’s as good a framework as any to work toward.

Whether you’re working in the four-or sixteen-bar phases favoured by rap; the eight-bar phrases favoured by soul, rock and R’n’B; or the twelve-bar phrases favoured by blues, if you’re want to fit it all into three minutes, then 96 bars at 128bpm is the perfect solution.

Perfect for a record producer, perfect for a radio show, perfect for a pop song.

But surely ‘neat maths’ isn’t the only reason that 128 is heralded as the magic number? Good music has always been so much about heart and guts and passion, not just clinical calculations.

Well, the numbers is just one part of it. The mysteries of 128bpm don’t just appeal to mathematicians. Nerds of all stripes have been trying to get to the bottom of it. And, just as Zac implied at the start of his little speech, there is also a physiological aspect to this whole thing.

The Science

The idea that different types of music can create distinct physical reactions in a listener is nothing new. Scientists have been studying the effects of music on the body for over a hundred years now and it probably won’t surprise you to learn that they’ve discovered… it has some.

A lot of the study into music’s effect on the heart has been conducted with an eye to using it for medical and therapeutic reasons – to help in the fight against cardiovascular disease, to help prep people for surgery, or to aid rehabilitation after heart problems. All of which is fair enough. There’s probably not much grant money specifically set aside for conducting experiments to prove or disprove the statements that Zac Efron makes in the We Are Your Friends trailer (nor would there be much subsequent use for the findings).

However, the broad strokes of the more medically-minded studies deal with what we’re after, and they show pretty much exactly what you’d expect too. Listening to calming, classical music can reduce your heart rate; listening to heavy metal or techno can cause your heart rate to rise.

So the claim that you can rock a party by using music to alter your audience’s heart rate is not entirely without foundation.

But is 128bpm really a good rate to have your heart at? What would cause a human heart to beat that fast?

Moderate exercise is one. For the sorts of young, sexy things that Zac Efron is spinning choons for 128bpm is somewhere between 55-65% of their maximum heart rate. Having your heart beat at that speed also happens with the type of endorphin-releasing exercise that ‘vigorous dancing’ falls under.

MDMA is another. Popular with many clubbers, a 125mg dose of the stuff will cause a person’s heart to raise by 30bpm.

If Efron’s voodoo DJ skills are to be believed, the effect of MDMA could be adequately recreated musically by playing Call Me Maybe by Carly Rae Jepsen (120bpm) immediately after All The Things She Said by t.A.t.U (89bpm) – which seems unlikely. The fact that the market for narcotics still exists, despite thousands of songs with a 30bpm disparity being freely available at the click of a few buttons, means that there’s probably a little more to it.

With proper scientific evidence suggesting music can alter a listener’s heart rate, and 128bpm is in the range of heart rates associated with clubbing (be it chemically or physically induced), there is every chance that hearing that same tempo in the rhythm of the music could artificially help to recreate some of the good feelings associated with dancing or being smacked off your tits on Molly.

And it’s certainly more credible than another of the theories put about in some less-rigorous quarters that 128bpm is the same pace as a foetal heart rate, and hearing it returns the listener into a pre-natal trance-like state of bliss.

The Practice

‘Theory’ and ‘evidence’ are all very well and good, but what about in practice? Has 128bpm created a single example of successful, party-rocking music? We took a quick look down a list of the most successful singles of recent times. And what did we find?

I Gotta Feeling – The Black Eyed Peas (15 million worldwide sales)
It’s not the only Black Eyed Peas song to use 128bpm – The Time (Dirty Bit) did too, and sold 7.3 million worldwide going to number one in many countries – but the Grammy-winning I Gotta Feeling was the most successful song of the 21st century by quite some margin. Until Happy by Pharrell Williams (160bpm) knocked it into second place last year.

Moves Like Jagger – Maroon 5 (14.4 million worldwide sales)
Despite being annoying as fuck (whistling in pop being second only to ukulele usage as the worst choice in musical history) the presence of a 128bpm count clearly helped to make this song Maroon 5’s biggest hit.

We Found Love – Rihanna feat. Calvin Harris (10.5 million worldwide sales)
Calvin has plenty of 128bpm form (Summer, Outside, Bounce); Rihanna does too (S&M, Where Have You Been?) so it makes sense that, together, they’d sell an absolute buttload using that tempo.

All of David Guetta’s back catalogue
If David Guetta has another tempo setting on his laptop, someone should show him how to use it. It’s pointless listing absolutely everything he’s ever done, but it’s all set between 126-130bpm with Memories, Where Them Girls At?, Turn Me On, Who’s That Chick?, Lovers On The Sun, Love Don’t Let Me Go, Just For One Day (Heroes), Without You and Crank It Up all being set at 128bpm.

It’s not just modern pop hits either. 128bpm has classic, historical precedent too. Frankie Goes to Hollywood’s Relax, The B-52’s Love Shack, House Of Pain’s Jump Around, Salt-N-Pepa’s Push It, George Michael’s Faith, Snap’s Rhythm Is A Dancer.

Maybe, for all his laughable posturing, Zac Efron actually has a point here? Maybe what he’s saying, ridiculous though he makes it sound, is hitting at something like a universal truth?

But if that’s the case, one final question remains. How, then, did the movie bomb so badly?

We Are Your Friends’ opening weekend was a huge disaster. Huge. A Top 10 All-Time Worst taking at the box office. Just $1.8million from over 2,000 theatres. Or $758 a theatre – which is Run For Your Wife sort of figures.

People love this sort of nuts-and-bolts numbers shit when it’s Malcolm Gladwell doing it, or the guys who wrote Freakonomics. So why is no-one paying attention when it’s Zac Efron giving a pop-science lecture?

Does no-one trust him to tell us the truth about music? Or is it that we don’t really like it when something we hold so dear to our hearts is stripped down to its component parts and picked over? It’s always said that, in comedy, dissecting a joke is like dissecting a frog. Nobody laughs and the frog ends up dead.

So maybe the best music, like the best comedy, is best left unexamined.