You can load them to Apple Music, but you can also load them as your local library.  See below:

Fix for Libraries on external drives or NAS on Mac (Error 913)

I could not access my music, which is sitting on an exteranl drive connected to a MacMini M2. Kept getting the Error 913. Here is a fix for that.

100% credit to the OP

https://en.community.sonos.com/controllers-and-music-services-229131/how-to-solve-the-error-913-music-library-on-a-mac-6894161?postid=16732714#post16732714

Video tutorial

https://www.youtube.com/watch?v=kjhKhDuvgDY

This worked for me after some screwing around. I still have lost access to my playlists but I can at least use the music files now.

Thanks for this. I’m using a PC. I’ve managed to get the titles to show now but are all greyed out. Any ideas?

Album Art is a work in progress.

Sorry. I meant the titles are listed but greyed out so I can’t play them

Hey everyone

I have linked my gmail account to SONO's. Problem is no playlists or any music comes up - i think becuase i have a youtube profile, within my gmail account, and SONO’s is pulling data from my gmail account, but not the youtube profile, if that makes sense.

Within my Gmail account I have a youtube profile. When I open SONO's to play yotube music it pulls my gmail account, because that's the email that it is registered to, but doesn't pull my youtube profile associated with the account, thus no music/playlists are available.

I can't figure out how to move my youtube profile back in to my gmail account. I cant figure out how to load my youtube account in sonos.

I am going to get YouTube Premium, because i have a lot of saved music and playlists on youtube, but want to make sure this works first.