The title of the author, or the title of the CD? Or perhaps it's a track title?
Comments do not exist to explain basic everyday concepts, nor basic linguistic skills.
You might as well ask "what's a CD?".
There's also no reason to believe someone with byzantine naming practices is going to be any better at documentation anyway.
And why would a function for adding to a CD have an integer parameter named "tracks"? (If your next argument is "maybe it's for the track number"... Bad name! Bad code!)
Finally, context is important, and considering a single function in isolation and thinking up all the ways in which it might be ambiguous (though I've yet to see anyone identify a plausible way in which this one could possibly be) is ridiculous. In all likelihood, the behavior of a function is even more obvious in the overall context of the system/API it's part of.
What I do mean to suggest is that while in any half decent codebase, addCD should be unambiguous, someone thinking title is ambiguous isn't having a stroke -- at worst they're being incredibly jaded. API design is nontrivial, people make mistakes in the trivial cases distressingly often (due to laziness, lack of familiarity, wildly different backgrounds, or any number of other reasons), and relying on context too much has it's own problems anyways.
For example: We're missing it in the very snippet we're discussing. There's no class shown. You're filling in the blanks with reasonable code. I've seen far too much unreasonable code to dismiss it when talking coding styles, and even reasonable code is only a botched refactoring or two away from being unreasonable.
public void addCD(String cdTitle, String cdAuthor, int numTracks, int durationInMinutes)