Biggest omission: "Marian the Librarian" from The Music Man. Surely this is the grandaddy of all librarian songs, but perhaps it's just too ancient and unhip to be considered.
Biggest stretch: "Fun Fun Fun" by the Beach Boys. You can hardly say that this song is about libraries or librarians. A library is mentioned in passing as a convenient lie the young woman in the song tells her old man so she can go out cruising--no one in the song actually sets foot in a library. And apparently it's not a very good lie, since her daddy sees right through it and takes the T-bird away.
Most of the songs on the list seem to be about having sex in the library or sexual fantasies about the librarian. I'm working on a few myself:
"Horny for Your Hornrims"Songwriting...not my thing.
"The Book of Love is Overdue"
"I'm Dewy for Your Decimal System"
"Hit Me! (With Your Late Fees)"
"Shhhhhhhhhh!ake it, Book Baby"
"I Can't Relax (When We're in the Stacks)"
"(Just Can't) Keep It Down Please!"
"Slippin' It Into Your Return Slot"