Here I do some analysis of the Beatles songs authorship. Only official authorship data is analyzed, i.e., all non-cover songs belong to Lennon-McCartney, Harrison, or Starkey. Sure, the lion share of the Beatles songs is attributed to Lennon-McCartney. But there is some interesting information behind it to reveal.
From all Beatles songs, about 88% are written by the members, and from these about 87% are written by Lennon-McCartney. Harrison has about 12%, Ringo only 1%.
Lennon and McCartney as solo singers sang about the same amount of the songs they wrote together, about a third each. Other songs they wrote were sung by other Beatles members or in cooperation with them. Both Harrison and Starr sang songs by Lennon-McCartney (two and four, respectively), while the opposite never happened.
With time, the share of Lennon-McCartney songs is gradually rising to the maximum of about 90% in 1967, and then is falling down a bit. But if we exclude cover versions, the share of Lennon-McCartney songs is actually slightly falling with time, while Harrison's one is generaly rising.
Median lengths are different only a little; songs by Starr are the longest, by Lennon-McCartney are the shortest, and by Harrison are in between. Songs of all authors have the same median number of words in titles: it's three. But all of them, except Starkey, have many songs that have more. Harrison's songs has the shortest lyrics, Lennon-Mccartney goes second, and the longest lyrics belong to Ringo's songs. Still in all three parameters Lennon-McCartney songs have most number of outliers and higher range.