Note the information below is current as of 2/13/23 for MacOS Ventura 13.1.  Lord knows what changes the winds of times and whims of Apple Software Engineers will bring.

So like many folks in this forum, I’ve been frustrated by the Sonos Library  recently refusing to recognize new playlists.  I periodically copy my Apple Music library and related files (the whole darn …/Music folder) to a shared drive that Sonos has access to.  Doing an index from the Sonos app picks up new music, but recently tends not to recognize new playlists even with repeated indexes, even deleting and recopying the music library, or sacrificing a chicken under a new moon, the whole drill.   No love on new playlists.  

After a bit of digging around I think I know what happened and how to fix it.   So in the old days of iTunes, Apple would automatically generate and keep up to date a file called iTunes Music Library.xml, stored in …/Music/Itunes/.   Sonos indexing apparently uses that file to do its magic. 

Cue dark clouds and ominous music. 

When Apple divided iTunes up into Music, TV, and Movies apps, the functionality of automatically generating and maintaining the IT Music Library.xml file  went away.   Apparently, the playlist info got moved into the actual library database file, but that’s not where Sonos is looking for it.  So…

Good news is that Apple stills provides the ability to generate the xml file manually.  So my new workflow on updating my Apple Music library

1. Make whatever changes I want.  Close Music app
2. Copy the entire top level …/Music folder to my shared drive (probably overkill, but I don’t want to spend the time figuring out what I have to copy or not). 
3. (New step) In Music App click on the file menu, go to library and then export library (File>Library>Export Library).  By default Music appears to want to put this on the desktop and call it library.xml.  For this to work, you’ll have to rename the file to iTunes Music Library.xml and then copy it to your shared location (same place as step #2) in the iTunes sub folder, so …/Music/Itunes/
4. Now, go into the Sonos App and do an index and new playlists should show up.

Yeah, this is a bit of bailing wire and duct tape approach, but I want to keep my main library on my laptop for access when I’m not on the net so this is a solution that works… for now.