> This guy is fresh out of college and should know not to name variables like this....

> For the record I'm a senior for CS.

That's a poor form of argumentation.

In your example, assuming the MusicMP3 variable is local, and the function is reasonably short, then it is preferable to use a short name such as "m" over a longer but equally uninformative name such as "mmp3". In programming just like in mathematics, we are often more interested in how values interact with each other than with what they are. Short names makes the interactions easier to see, e.g:

    diag_len = sqrt(w * w + h * h)

Is much better than:

    rectangle_diagonal_length = square_root_of(rectangle_width * rectangle_width + rectangle_height * rectangle_height)

Maybe I have still not convinced you and that is ok. But now you see it is a matter of taste. So why get upset over if someone names a variable "m" instead of "mmp3"? Is it the end of the world?