To add music or audio pieces to your portfolio we recommend that you do this by adding the audio to Soundcloud and then adding the Soundcloud URL on your portfolio as an article URL. This way it will embed the Soundcloud player on your portfolio which is a far better player than we could build.
The same thing happens with YouTube or Vimeo links.
The reason we don't support uploading these kinds of media files directly is because of the complexity to process the media so it works on every kind of browser and device as well as to create a good embedded player. The likes of SoundCloud and YouTube obviously do a much better job of this than we can so we think it makes sense to focus on the bits that don't require re-inventing the wheel.