Bernd Thyssen/photography partnership via Getty Image
For nearly a century, jazz musicians and scholars have debated the answers to musical mysteries. Legendary jazz trumpeter Louis Armstrong once said, “What is this called swing?”
Swing has long been considered an integral part of nearly every kind of jazz, from traditional jazz to bipop to post-bop. As Ella Fitzgerald and many others sing, “Without that swing it doesn’t make sense.” Swing might be described as a rhythmic phenomenon in jazz performance, the impetus and groovy feeling that makes you want to move with the music.
Yet a precise definition of swing has long remained elusive for musicians and academics alike. Big band-era jazz trumpeter Cootie Williams once reportedly joked about swing, “Explain it? I’d rather work on Einstein’s theory.”
Fittingly, physicists now think they’ve found the answer to the swing secret. And it all has to do with the nuances of the soloist’s timing.
The elusive sense of swing in performance
Ask any jazz musician what swing is and you’ll probably get the same answer that Christian McBride gave me.
“Swing is a feeling,” says McBride, multiple Grammy-winning jazz bassist, music educator, and NPR host jazz night in america. “There is a certain language, there is a certain rhythmic inflection.”
Swing has one distinguishing element that is easy to hear. It has to do with how eighth notes are played. Instead of playing it straight, like this…
… In jazz, these notes are swung. That is, the downbeat (or every other eighth note) is played a little longer, and the offbeat notes in between are shortened, creating a scurrying rhythm like this.
But jazz musicians know that technique alone doesn’t explain swing. After all, computers can swing sounds too.
“Computers are not the only “Excuse me, you’re not going to swing that hard, are you?” McBride says, “I still haven’t gotten the feel of a real proper swing that’s human feeling.”
McBride explains that that sense of swing occurs when musicians interact while playing. “For me, I think you need to lock people in and say, ‘OK, here’s the time, here’s the rhythm,’ so everyone collectively, musicians and listeners alike, can say, ‘Oh, yeah. You know… that feels right,’ you can think.”
But how exactly do musicians play each other to create that sense of swing? That’s what Theo Geisel wanted to know.
Geisel is a theoretical physicist at the Max Planck Institute for Mechanics and Self-Organization and the University of Göttingen, Germany. He spent decades studying the physics of synchronization, such as how billions of neurons in the brain work together. He is also a passionate amateur saxophonist. He also forms bands with other physicists. (They play at conferences.)
Geisel is now retired. That gave him more time to use his theoretical physics toolkit to explore cosmic mysteries such as: How do musicians synchronize when trying to create swing in jazz?
“The general idea is that when musicians play together, they should be as in sync as possible.
However, since the 1980s, some scientists and musicologists have argued that the sense of swing is actually produced by slight timing discrepancies between different musicians playing different types of instruments. To test this theory, Geisel and his colleagues took jazz recordings and used a computer to manipulate the timing of the soloists relative to the rhythm section.
“We had experts — professional and semi-professional jazz musicians — rate how swinging these different versions of the song were,” he explains.
The song they manipulated was a recording of the jazz standard “Jordu” written by Duke Jordan. For example, in one version the piano soloist started playing at exactly the same time as the rhythm section. In another version, the soloist’s downbeat started just behind the rhythm section, but the offbeat was not delayed.
Here’s what those two versions sound like:
Didn’t see the difference between the clips? No problem. Geisel says most people probably don’t. After all, the timing delay we’re talking about is negligible, only 30ms, or a fraction of the time it takes to blink.
Still, the jazz musicians who rated the clip rated it.
“They could see the difference, they could feel the difference,” says Geisel. “They told us they could hear friction between the rhythm section and the soloists, but were surprised they couldn’t pinpoint exactly what was going on.”
According to Geisel, expert musicians were nearly 7.5 times more likely to rate the version with downbeat delay as having a more satisfying swing feel.
In another part of the experiment, the researchers also analyzed a database containing more than 450 recordings of jazz soloists, including performances by Dizzy Gillespie, Joshua Redman, Charlie Parker and others. I found that almost all of them used a small downbeat delay for the rhythm section. “There were very few exceptions,” says Geisel.
He says these small timing delays are no coincidence. They’re codified, but musicians probably just do it intuitively.
So have scientists finally cracked the Swing code?
“We solved a lot of things,” says Geisel. But there are some mysteries in individual artistry that science will never solve, he says.
For jazz musicians looking for swing secrets, McBride’s advice is to “study the greats.”
“There are spiritual answers, and then there are scientific answers,” says McBride. “You need to listen to people who are doing well. Louis Armstrong, start there. Nicholas Peyton isn’t a bad start if you want to go listen to people who can really shake their butts off.” I don’t think Branford Marsalis would.” Bad start. ”
If you listen carefully, he says, the mysteries of rhythm and timing will eventually be revealed.
This story is part of the regular science series Finding Time — A Journey Through the Fourth Dimension to Find Out What Motivates Us.