In 1979, songs stopped speeding up

“Honky Tonk Women” starts at 109 beats per minute and ends at 127.

That’s eighteen beats, sixteen per cent, and in 1969 nobody thought of it as a fault worth fixing. The record went out that way, and live the Stones kept doing it.

For decades this was something you argued about by ear. Somebody has now measured it. Properly.

David S. Carter and Ralf von Appen built tempo maps for 255 singles that reached Billboard’s year-end top 15 between 1966 and 1995, a corpus wide enough that the shape of the change stops being a matter of taste and starts being a line on a chart.

The work is published in Intégral, the music theory journal of the Eastman School of Music.

The drift wasn’t sloppiness

Here’s the thing that turns the cliché over: where bands sped up, they sped up in the right places.

The Beach Boys’ “I Get Around”, from 1964, holds its verses between 140 and 145 beats and picks up roughly ten more on the choruses, climbing again for the last one.

That isn’t a drummer running away, it’s a shove that lands exactly where the harmony does, which is the opposite of losing control and is closer to arranging with the tempo itself.

“She Loves You” does it too.

It works in reverse as well. Joan Jett’s “I Love Rock ‘n Roll”, from 1982, drops 4.3 per cent through the pre-choruses. That brake is what loads the chorus behind it.

None of that was exceptional.

Before 1978, 46 per cent of the songs in the sample finished at least three per cent faster than they’d started, and 22 per cent finished at least five per cent faster, which makes the drift not a quirk of a few sloppy sessions but the ordinary condition of a hit record.

Listen while you read

The year the line goes flat

The researchers measure variability with a coefficient of variation. The year-by-year medians tell one story.

1972 sits at 1.51 and by 1978 it’s down to 0.84. In 1979 it collapses to 0.46, and from 1982 onwards it never climbs back above 0.5. The 1994 median is 0.03.

Counting heads is blunter still: before 1976 not one top 15 song comes in under 0.5. In 1978 it’s three out of fifteen, and in 1979 it’s ten.

The thresholds tell you what’s behind a number. Under 0.2 means a sequencer, a drum machine or a tape loop, while between 0.2 and 0.5 is a human drummer playing to a click. Between 0.5 and 2 there’s nothing helping at all.

The machine that drifted

Now the part you wouldn’t guess. It comes from the man who was there.

Steve Levine produced Culture Club. He explains that the Linn didn’t run on SMPTE but on a pilot tone, which meant you programmed your parts into the machine, hit play, and printed that tone down onto one track of the multitrack so that everything recorded afterwards could be hung off it.

On “Karma Chameleon” it gave way.

Because the tempo was running so fast it was actually skipping the pilot tone and running free, and on the time that I printed it, the song actually sped up very slightly as it got nearer to the end.

So the machine bought to kill the drift drifted, on a 1983 record that charted more or less everywhere, and nobody noticed for years.

Worth adding how Levine actually worked, because it isn’t what the story implies. The Linn never replaced the drummer: it laid a backbeat underneath, and Jon Moss played over the top.

“Every Breath You Take” runs on the same principle. An Oberheim DMX supplies the kick while Stewart Copeland overdubs the snare, the hi-hat and the cymbals on top of it, so the record you know is half machine and half one of the most recognisable drummers of the decade.

Freedom started faking it

Once the grid had won, the breathing didn’t disappear. It got staged. There’s a difference.

There’s a moment in “I Will Survive”, a little past two and a half minutes, where the record seems to stall and gather itself. It doesn’t stall. It lasts precisely three bars at the click tempo of 116. The drummer, James Gadson, confirmed the click was running.

The J. Geils Band do the same thing in “Centerfold”, where the suspension runs nine clicks long.

Rubato had become a quantity you could count.

Then someone went back and tidied up

The last stretch of the study is the uncomfortable one. It has nothing to do with the seventies.

Several digital remasters have quantised the drift out of the original records without saying so. The Bee Gees’ “Stayin’ Alive” goes from 0.10 to 0.02 in the 2009 remaster. The same happened to “More Than a Woman”, to Queen’s “Another One Bites the Dust”, to Donna Summer’s “Bad Girls”, to Prince’s “When Doves Cry”.

Which means the version you stream today may no longer carry the movement the record was made with, and nothing on the page tells you so.

We spent an afternoon putting a couple of these side by side on headphones. The difference isn’t where you expect it. You don’t hear “tighter”, you hear something that stops pulling you forward.

One last detail, for anyone who believed otherwise. That ticking inside “Blackbird” isn’t a metronome. It’s McCartney’s foot.