Music-ky Wiki

Various song lists at Wikipedia:
(idea via brykmantra)

List of songs with titles that don't appear in the lyrics

List of songs over fifteen minutes in length (betcha didn't know this list includes a Beatles song)

List of songs whose title constitutes the entire lyrics

List of sets of unrelated songs with identical titles

List of song titles phrased as questions

List of songs whose main title appears more than twenty times in the lyrics

List of songs that use the same rhyme throughout

List of songs deemed inappropriate by Clear Channel following 9/11

List of songs titled as acronyms of initialisms