Note re Beatles songs, per Kaleea's message:

John and Paul had agreed at some early date to share songwriting credit as "Lennon/McCartney." As time passed, they gradually stopped co-writing as each began to work by himself, but their contractual partnership was still in force. This means that most of the later "Lennon/McCartney" songs were actually written by one or the other of the two, not by both.

The smaller number of Beatles songs written by George and Ringo were never attributed to Lennon/McCartney, but to Harrison and/or Starkey/Starr. (George wrote one or two songs per album, but there are few if any Ringo compositions in the Beatles catalog ~ his vocal solos were mostly "covers" (e.g., Buck Owens' "Act Naturally"). I know he is credited as co-writer of "Photograph" with George, but I believe that was during the post-Beatles era.)

Of course, the truly ignorant may indeed lump all Beatles songs together as Lennon/McCartney composisions, just like somebody attributed Steve Goodman's song to one of the many singers who recorded it. But any song atributed to "Lennon/McCartney" by a reputable source was definitely written by either John or Paul, if not both. George's songs were all properly credited to "Harrison," and I believe he may even have had a different publishing company from John and Paul's. Same for whatever Ringo might have contributed.

I'm sure that I'll be hearing back from someone who can identify Ringo's compositions. Was he credited for "Yellow Submarine"? Or maybe "Octopus's Garden"?