We backed up Spotify (metadata and music files). It’s distributed in bulk torrents (~300TB). It’s the world’s first “preservation archive” for music which is fully open (meaning it can easily be mirrored by anyone with enough disk space), with 86 million music files, representing around 99.6% of listens.
If I ran mb, I would be cautious importing the data directly. I’m sure Spotify would consider it trade information and go after anyone directly using it. However if a few million people added the tracks with individual edits then it probably won’t take too long.
I thought metadata couldn’t be copyrighted though?