"I have a song that is a single track with audio on the beginning and end and a big blank area in the middle, how can I trim the mp3 to reduce the amount of time the blank audios duration?"
There is an app called "mp3 trimmer" that can edit mp3's without converting them. I believe it's shareware. Worth looking into.
The value of "mp3 trimmer" is that you are editing the mp3 itself. This means you don't have to first un-compress the file (usually to .aiff format), then edit it, then RE-compress it back to mp3 (which because of the "lossy" compression may further deteriorate the source audio).
Probably the easiest way is to decompress the file (you could open it with GarageBand), edit it, then re-compress it back to mp3 format.
But again, the edited final version may not sound quite as good as before.
