The Beatles‘ 1968 track ‘Ob-La-Di, Ob-La-Da’ has been declared the most perfect pop song ever written by researchers at the Max Planck Institute in Germany.
The scientists analysed 80,000 different chord progressions from 700 songs recorded between 1958 and 1991, using machine learning to give a score to each chord based on how “surprising” it was compared to the chord preceding it.
Chord sequences from 30 of the songs were then played to 39 volunteers, stripped of lyrics and melody to make the source track unrecognisable. The volunteers were asked to rate how enjoyable they felt each chord to be.
The research found that when the volunteers were relatively sure what chord was coming next, they enjoyed being surprised instead.