Fixed a bunch of issues that were causing PHP warnings/errors that were being ignored before.  Also switched out the jquery.fileinput.js with the jQuery File Upload widget since it enabled me to clean up that code a bit (although, the price is a larger library)  In the future I might try to build a custom uploader for the music files that's based on the jQuery File Upload widget rather than using plupload.  That will even out file size discrepancy.