Fab Four’s element of surprise strikes chord
John Lennon is said to have openly detested Ob-La-Di, Ob-LaDa, dismissing it as ‘‘more of Paul’s granny music’’. Now, in a nice example of ‘‘how the life goes on’’, scientists have suggested that the Beatles number is close to being a perfect pop song.
Researchers used statistical models to analyse 80,000 chord progressions from hundreds of pop music hits. They concluded that for a song to strike a chord, its chord sequences must give rise to uncertainty and surprise.
‘‘It is fascinating that humans derive pleasure from a piece of music just by how sounds are ordered over time,’’ Vincent Cheung, a PhD student at the Max Planck Institute, said.
‘‘Songs that we find pleasant strike a good balance between us knowing what is going to happen next and surprising us with something we did not expect.’’
The research also found that activity would flare in a region of the brain connected with musical pleasure when we were unsure where a song would next turn. Songs with these qualities include There She Goes by the La’s, Red Red Wine by UB40 and
Sweet Surrender by Bread. Alongside Ob-La-Di, Ob-LaDa, the most effective songs of all, according to the analysis, included Hooked on a Feeling by BJ Thomas and Invisible Touch by Genesis.
The researchers used a machine learning system to assign values to the chords from more than 700 songs that appeared in the US Billboard Hot 100 chart between 1958 and 1991.
Each chord was essentially given a score of how surprising it was, given the chords that had preceded it.
The analysis also assessed how unusual, and hence how unexpected, the chord sequences were.
The researchers then played the chord sequences from 30 of the songs to 39 volunteers.
Each chord was played for about 2 seconds and the sequences were stripped of other elements, such as lyrics and melody, making the source track unrecognisable. The subjects were asked to rate how enjoyable they felt each chord to be.
The results suggested that when the subjects were relatively sure about what chord to expect next they would find it pleasant when they were surprised instead.