Tripped over this (minor) issue whilst fighting a different problem:
SETUP: Mac running Sonos Controller 16.4.2.
music (nee iTunes) library lives on the Mac (Users/dan/music/iTunes)
iTunes library exported to "iTunes Music Library.xml"
Mac iTunes file structure entirely copied to USB drive hanging off router (\\NASMOUNT\iTunes)
Sonos library location only knows \\NASMOUNT\iTunes.
This has been working for years.
I recently noticed that Sonos had a couple of extra imported playlists: Library and Music. They each appear to contain all songs.
Reading posts here, it sounds like Sonos no longer needs the XML file, so I tried different variations.
1) updating library after deleting xml file on the NAS:
library and music are created in imported playlists, my imported playlists are there.
xml file on Mac was modified.
this was surprising, as I wasn't aware Sonos knew about the Mac iTunes location.
2) updating library without xml file either on NAS or Mac iTunes library
Mac iTunes XML file is created
imported playlists are empty
3) updating library after exporting iTunes library to XML and copying it to NAS
imported playlists are there, but so is a new on called Downloaded - seems to contain all songs
library and music imported playlists disappeared
the Mac iTunes XML file was modified, the XML file on the NAS was not modified.
I have verified there is no other xml file in either of the file structures.
apparently, Sonos will create it's own XML file (in Mac iTunes path), but it doesnt handle iTunes playlists very well.
This make any sense? Like I said, not a big issue, but it is screwy...
thx
Dan Wills