Cas

Sadly, neither have I- in the closed source world there’s stuff like Soundslice which is pretty good but nothing really open source

It can, and it’s quite good! But I mean something more like a self hostable archive.

I would really like to see something like Jellyfin/Komga but for sheet music. There’s a software in early development called Sheetable that stores it in PDF format, but I really want to see something that has MusicXML support so that sheets can be played back.