If it's your own music, you could also try to make a Youtube account (very easy), upload your music to Youtube, and then make a journal with the Youtube link.
I know that's not as easy as direct upload, but if you insist on submitting your songs in DA, that seem to be the only way. 

  

dA doesn't allow music uploads in case of copyright violations. It is an interesting idea in theory, however, but I bet it would be abused by stupid people uploading copyrighted music onto this site. Soundcloud is already misused for the latter reason.

You can't submit MP3 or other music files for the simple reason that dA doesn't want the demons and trolls at the RIAA to come down and club the company asunder.

You can't upload them here since there's a lot of issues with copyright..and I guess deviantart just wants to stick with art and literature only for now.

Music submissions aren't accepted here for copyright liabilities.  Sites like bandcamp.com/ and soundcloud.com/ are better-suited for sharing music anyways.