It doesn’t mean anything if he doesn’t have that swing, all you have to do is stagger your timing.
For decades, fans of jazz music have debated why some songs have swing, the characteristic rocking sensation that forces feet to tap and heads to dance. Now scientists may finally have an answer to Louis Armstrong’s classic song “What’s this thing called swing?” and the secret is in the timing of the jazz soloists.
After listening to original and digitally enhanced piano recordings, jazz musicians were seven times more likely to classify music as “swinging” when the soloist’s timing was partially delayed relative to the rhythm section, the researchers report Oct. 6 in Communications Physics.
In jazz, musicians are trained to balance eighth notes or extend the length of their downbeats (every other eighth note) and shorten the middle beats to create a galloping rhythm. But technique alone doesn’t explain the swing, says physicist Theo Geisel. computer generated jazz songs with balanced eighth notes still lack the rocking feel of the style (Serial number: 02/17/22).
Previous research hinted that the swing might arise from differences in the time between musicians within a band (Serial number: 2/1/18). So Geisel and his colleagues modified only the timing of soloists in jazz recordings on a computer and asked professional and semi-professional jazz musicians to rate the swing of each recording.
Musicians were nearly 7.5 times more likely to judge the music to be more swinging when soloists’ downbeats lagged minutely behind the rhythm section, but their offbeats did not.
Most musicians didn’t know what was causing the effect, says Geisel, of the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany. “Professional jazz musicians who have played for many years have apparently learned to do this subconsciously.”
The researchers also analyzed 456 jazz performances by various artists and found that almost all soloists used strong delays, with an average delay of 30 milliseconds. This average held true for the bebop, swing, and hardbop jazz subgenres, though there were some variations, says Geisel. “For faster tempos, the delays get smaller.”
Looking ahead, Geisel intends to investigate how “relaxed playing,” a popular style of delaying both downbeats and offbeats in jazz, influences swing.