Am 29.10.19 um 23:09 schrieb L A Walsh:
p.s. - oh screw it, has anyone tried classifying music into the pre-existing '8' categories (now over 200 and still not a free-format list) that were provided by some music players 20-30 years ago and really thought that just one category applied to their music? Is software that different?
That's an interesting direction to look in: what other classifications are out there and how well do they work? I think art is always a bit hard to classify, although art historians try to put it into boxes as much as possible.
But scientific papers are actually classified by systems very similar to rpm Group tags: * the Mathematics Subject Classification (MSC) , * the Physics and Astronomy Classification Scheme (PACS), discontinued but apparently still used , * the classification of papers in arXiv .
These are all hierarchical, and either allow just one classification, or have a primary classification.
These classifications are probably not always perfect, and just like with Group tags it might happen that no group matches exactly, or multiple groups apply. Yet judging from their usage the benefits seem to outweigh the costs.
Best regards, Aaron
 https://en.wikipedia.org/wiki/Mathematics_Subject_Classification  https://en.wikipedia.org/wiki/Physics_and_Astronomy_Classification_Scheme  https://arxiv.org/