Lennon or McCartney? Scientists decode who wrote Beatles' 'In My Life'

Paul McCartney misremembers having written the Beatles' song 'In My Life', say Harvard scientists who solved a long-standing musical mystery, attributing the authorship of the 1965 track to John Lennon.

The use of statistical techniques to determine authorship - called stylometry - is best known for revealing that Shakespeare collaborated with Christopher Marlowe on the Henry IV play cycle.

In textual analysis, it is not the unusual word choice that betrays the hidden voice, but the recurring patterns of common words, such as prepositions, that mark the probable identity of one person alone.

A surprisingly large number of songs by Beatles have disputed authorship.

For example, no one knows who wrote the music for "In My Life," a track from the 1965 album Rubber Soul, which is ranked 23 on Rolling Stone's The 500 Greatest Songs of All Time.

Both Lennon and McCartney remembered differently.

"We wondered whether you could use data analysis techniques to try to figure out what was going on in the song to distinguish whether it was by one or the other," said Mark Glickman, senior lecturer at Harvard University in the US.

Researchers "decomposed" each Beatles song from 1962 to 1966 into five representations. Each representation consisted of the frequency of occurrence of a set of musical features within each song.

"The basic idea behind our approach is to convert a song, whose musical content is difficult to quantify in any direct way, into a set of different data structures that are amenable for establishing a signature of a song using a quantitative approach," said Glickman.

"Think of decomposing a colour into its constituent components of red, green and blue with different weights attached. We're doing the same thing with Beatles songs, though with more than three components. In total, our method divides songs into a total of 149 constituent components," he said.

Researchers characterised melodic notes - notes sung by the lead singer and recorded the frequencies of occurrence of chord transitions, that is, one chord followed by another chord.

Again, certain uncommon chord transitions were aggregated into single categories. They then recorded the frequencies of consecutive melodic note pairs.

Finally, they decomposed songs into four-melodic note "contours."