Hitting the Books: How to build a music recommendation 'information-space-beast'

As of October, singers, songwriters and music makers are uploading 100,000 new songs every day to streaming services like Spotify. That is too much music. There's no reality, alternate or otherwise, wherein someone could conceivably listen to all that even in a thousand lifetimes. Whether you're into Japanese noise, Russian hardcore, Senegalese afro-house, Swedish doom metal, or Bay Area hip hop, the sheer scale of available listening options is paralyzing. It's a monumental problem that data sc...