I was checking out the term Library Song, at Youtube, and these are the results that I found. Some are really amusing and a few have very interesting bits about how people perceive the library.
This is a song by a comedian, in the video there is an introduction to explain the origins of the song, and it was quite funny. The song is about librarians in general.
These two are made by students about their academic libraries.
This is a song being taught at a middle school.
This one is a library rap.