It ended up taking almost an hour to figure out. Downloading a file to the filesystem is nigh impossible on iOS, and there are no native apps which helped with the problem. I had to jump from questionable app to questionable app until one would let me "paste a youtube link in" which eventually worked; albeit, it still won't let me play my new song in the native music app! It feels like user hostility and it surprises me that this behavior doesn't drive more people wild.