Pandora is based off of the "Music Genome Project" which was a massive effort that took tons of music efforts to make happen. Experts literally sat down and deconstructed individual songs by hand and gave them tags.

It's truly a historic achievement and it's almost sad how the massive effort mainly resulted in a private database that's primarily used for a failed Spotify competitor

I am 100% with you there. The things that could be done to advance the creation, understanding and appreciation of music from that work is staggering. It's sad that it's stuck in amber.