Not sure what i'm looking fore (matrix, db-like structure) to organize files by tags

i was messing around organizing my music files when i asked myself why windows nor linux offer a way to organize a folder by custom tags in a database-likle manner rather than hierarchically.

The problem i wanted to solve is the following: I have music files A title "tempest" from Beethoven, classical music in a piano only version. B title "whatever" from Mozart, classical music orchestrral D title "one winged angel" from Uematsu, classical style, game ost, orchestral C title "one winged angel" same as before, violin only, cover from Taylor Davis.

And whatever "main" information i use for grouping, makes listing files by any other category immpossible. Hence i whished to save files in an hidden folder with a simple increasing number.format, and have a program in which i can add files, add categories, search by tags, and end up with a list of the files i want. E.g. today i want to listen to all piano only pieces independently of their composer-time period.

I started making a structure of vectors containing vectors (aka matrix) but indexing lines and column by string started getting complicated when i want to remove a column. And searching files by tag would require me to have each tag as an object knowing all files that use it, and it starts becomming more similar to a 3d matrix. I though it would be better to think of this as a database, started with sqllite but ended with the problem of being unable to remove columns (i know i can create a copy etcc, but i wanted to avoid messy workarounds). Also an sql-like database wouldn't allow me to have an area dedicated to a list of random tags for each file without a definite category.

Is there any existing library that rather then working as an sql database offers me something similar to a search/insert optimized matrix for strings? I don't think i was the first one thinking about that, someone must have done something similar.