Spotify, hire musicologistsStrongly disagree with that. For one thing, Spotify already has an army of tastemakers spending all day assembling curated playlists. For another, they have the Echonest data which relies heavily on manual labeling.
But the major innovation in Discover Weekly was to use machine learning directly on mel spectrograms to figure out meaningful features for human taste. They still want to rely on their experts as much as possible (and hey, I don't blame them for not wanting to fire people), so they try to combine their expert's features with the algorithm's. But this introduces human biases again.
The problem is that when it comes to music, everyone's a missionary. Everyone wants the world to listen to the music
they are excited about. Professional opinion-haver about music is the dream job for many adults, much like chocolate factory taste QA expert is for 6-year olds. And they just can't separate their own opinions from objective truths very well. It's hard to be objective about something you love.
The real great thing about AI in recommendations isn't really the intelligence part. It's the "AO" - artificial objectivity. The algorithm is probably inferior to humans in some aspects (it can't interpret the themes in lyrics very well, for instance), but the advantage is that you have full confidence about
1. What information it actually might use, and
2. What it tries to optimize.
From point one, you can be sure that it's opinion on Smashing Pumpkins isn't affected by that annoying kid in 8th grade that used to listen to them. For point two, you can be sure it's really trying to find the music you will love, not what it thinks you should love.
To get it slightly back on track: I can't wait until an AI can do music history, or etymology, or economics, or history. Or matchmaking in dating! It will be useful long before it can match humans on intelligence. How great wouldn't it be to get results in those fields which you could trust were from a disinterested party.