Secret to great song writing!

WASHINGTON: What makes some music so enjoyable, and can science help us engineer the perfect pop song?

A group of researchers who statistically analyzed tens of thousands of chord progressions in classic US Billboard hits say they have found the answer, and it lies in the right combination of uncertainty and surprise.

Vincent Cheung of the Max Planck Institute for Human Cognitive and Brain Science in Germany who led the study told AFP the data could even assist songwriters trying to craft the next chart topper.

Writing in the journal Current Biology on Thursday, Cheung and co-authors selected 745 classic US Billboard pop songs from 1958 to 1991, including "Ob-La-Di, Ob-La-Da" by The Beatles, UB40´s "Red red wine" and ABBA´s "Knowing me, knowing you."

They then used a machine learning model to mathematically quantify the level of uncertainty and surprise of 80,000 chord progressions relative to one another, and played a small selection to around 80 human test subjects connected to functional magnetic resonance imaging (fMRI) brain scanners.

The scientists found that when the test subjects were relatively certain about what chord to expect next, they found it pleasant when they were instead surprised. Conversely, when individuals were uncertain about what to expect next, they found it pleasurable when subsequent chords weren´t surprising.