Stands for John Lennon and Paul McCartney.

At the very start of The Beatles' career, it was obvious that the pair would write most of the material (they did, in fact, write over 90% of the Beatles' original compositions). Before the first song was published, they decided that all the songs that they wrote together, as well as the ones they wrote separately, would be credited to them both. Thus, there are no Beatles songs credited to only one.

This proved to be critical on three levels:

  • It probably contributed to the stability of the Beatles, as they could be more free to write without thinking who would get the credit (and royalties). Queen, for example, almost broke up for a similar reason (Roger Taylor wrote I'm In Love With My Car, which was the B-side of Bohemian Rhapsody. He demanded equal royalties from the single's sale, which caused no end of conflict. In the end, Queen realised it was best to split things evenly, and in later albums there is no distinction as to who wrote what).
  • It gave Beatles fans lots of speculation as to who wrote what. It is easy to tell, for example, that Lennon wrote Lucy in the Sky with Diamonds and that McCartney wrote Yesterday. But some songs are not so obvious, and may even surprise you.
  • Near the end, when the heat was brewing between the two, it gave them a chance to piss each other off. Paul McCartney was (perhaps still is) angry that his name was on Revolution 9. Actually, as John was recording Revolution 9, Paul was sitting alone, and recorded Blackbird. Both expressed the need for freedom from the Beatles, but in such different ways!