https://phys.org/news/2018-07-lennon-mccartney-statistical-analysis-authorship.html

As Glickman explains, for most Lennon-McCartney songs, it is well-known and well-documented which of the two wrote the song. However, a surprisingly large number of songs (or portions of songs) have disputed authorship. As an 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. "So, 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," says Glickman.

With help from former Harvard statistics student Ryan Song, Glickman and Brown "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," says Glickman, "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." Glickman continues, "Think of decomposing a color 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."