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 recall correctly, Spotify streams ogg vorbis—not mp3, so that would be a transcode.
well, there is an option for “raw media download”, so I’m assuming turning that on will get you the .ogg files you seek if that’s important to you. I honestly don’t care that much as 320kbps .mp3s sound as good as anything else to me.