Lots missing on the song origins drop down.

Why can't I find my favorite song, "Old (Dog) Blue"?

Or my wife's favorite, "(El) (Senor) Don Gato"?
A hell of a lot of posts on that one.

or "Miserlou"? Arabic, Sephardic, Greek and tin pan alley origins discussed there.

I could go on- or is the list for selected popular hits only? Of the first four I looked for, the only one that showed up was "Bile dem Cabbage."