P.S. I noticed you tagged Photocrati, which is the same theme I am using. I tried uploading music on the blog through the “Theme Options > Customize Theme” section and it worked, so it is for sure not a Photocrati issue, it is WordPress.
I am having this same issue to on my site, and after a few hours I haven’t been able to find out any more info other than this is also happening with uploaded images for some people, it is a bug from the latest version, and no one has an answer on how to fix it. If there is someone that knows a way around this issue please let us know, it is driving me crazy!