User tagging isn't a panacea either, because people tag inconsistently, and people who tag a lot are probably not very representative.
For an extreme example of that, see the boorus. Some machine learning people have become interested in those, since they are huge dataset of extensively tagged material ... or maybe it's the booru people who have become more interested in machine learning. Either way, I'm sure they're great, if you're into waifu anime, porn, or waifu anime porn. Both types, country AND western, as they said in the Blues Brothers movie. Any tag remotely subjective (such as "beautiful", God help you) is going to be extremely coloured by the tastes of an extreme fringe.
At least, relying on fanatics to do the work for them, I assume they've got a handle on simple spam on the boorus. Commercial recommender service tagging systems don't have that luxury, and that's probably why they end up eventually removing them.
This is very true. I'd pay for a metadata-only / playlist service that works with Spotify/Tidal/Apple/local music.
And don't allow free-text tags. Instead you give a list of available tags - the lowest number needed to describe most tracks. I mean, let people add their own if they want, but you should ignore those while training the model.
I actually think that instead of trying to tag some specific mood (eg "happy") some sounds be a sliding scale between two opposites:
happy<-------|--->sad
Instrument tags are easier to understand. Give a list of instruments (or instrument types, because the user might not know precisely which woodwind or percussion instrument it is) with checkboxes beside each.
Some users will be experts because they play woodwind. Let those users apply to become experts, pass a test, "identify the instrument", and if they pass, give them half price subscription as long as they moderate X tunes per week.
For an extreme example of that, see the boorus. Some machine learning people have become interested in those, since they are huge dataset of extensively tagged material ... or maybe it's the booru people who have become more interested in machine learning. Either way, I'm sure they're great, if you're into waifu anime, porn, or waifu anime porn. Both types, country AND western, as they said in the Blues Brothers movie. Any tag remotely subjective (such as "beautiful", God help you) is going to be extremely coloured by the tastes of an extreme fringe.
At least, relying on fanatics to do the work for them, I assume they've got a handle on simple spam on the boorus. Commercial recommender service tagging systems don't have that luxury, and that's probably why they end up eventually removing them.