Music Player and Library

[yuutacchi]

I have been using and reading MacRumors forums for a few years now and using the mac and recently purchased a 2016 Core m3 Macbook to replace my 2012 Macbook Air. As a result, I handed over my Macbook Air to my father. To be honest, he used to be tech-savvy but now kind of lost track of new things. He used to manage his 70GB music library on Windows 10 using a local USB HDD and Windows Media Player and only switched just over a year ago to a NAS for his music library and he has been using since then WMP to manage his library from the NAS with a little workaround (creating symbolic link to make Windows believe the music is local). All in all, despite all this not being supported, it kinda worked although slowly. Maybe there is a thing or two you should know about WMP libraries

• WMP offers the possibility to not manage your files and to let you organize folders and song naming however you want (yes i know this a very very bad idea). However, the fact is that my father's music library does not follow any kind of pattern when it comes to file management
• WMP does not store cover arts in the files like most software, putting them instead as a separate cover.jpg/png file in each album's folder.

As a result, although he could use his old PC as a Plex or Subsonic server, it would require reorganising files and reassigning cover arts to most albums (which I've always encouraged him to do, even back on Windows). We've tried iTunes (importing files) but it takes forever. Clementine seems to not see many of the files in the library and Harmony Player fails to find music on the NAS.

So my question is: although I do know that using a server with proper file management would be a much better solution, do you know of any software that would allow to use the library directly on the NAS, "as is"?

EDIT: Kodi works perfectly but is totally not adapted to the usage