Pop music today is slower and sadder than it was in the past, according to researchers.
The researchers, from the University of Toronto and Free University of Berlin, analysed more than 1,000 hits from 1965 to 2009 and blamed the loss of the feel-good factor on wanting to be seen as serious and complex - and on listeners who like to think they are more sophisticated.
As a result of this, unambiguously uplifting songs like the Beatles' 'Help!' or 'She Loves You' are few and far between.
The researchers analysed tempo and key of many of the biggest hits of the last 60 years. In general, a happy song consists of a fast tempo and a major key, while misery is denoted by slow beats and minor key.
Modern pop songs tend to be slower, with just 100 beats per minute, compared with 116 in 1960s, and the average duration of a recording has increased.