I have folders of songs I import into iTunes of concerts that have, say, 15 songs in three sets. They are tagged correctly with the artist & album names and songs tagged disc 1- songs 1..5, then disc 2 songs 1..5, and disc 3 songs 1..5. iTunes displays correctly (grouped by disc) and plays in the correct order.
When synced with Sonos and I select the album the songs are sorted first as three songs "01", then three "02", etc. That is, the songs from different sets/discs are merged together.
I've seen other suggestions to edit the tags, and yes, I can re-tag the songs in iTune sequentially (song 1,2,3,...14,15), resync in Sonos as a workaround.
Does Sonos not look at the "disc" attribute when sorting songs in an album? Or is there something else confusing the sorting & numbering of the tracks in Sonos Controller?
I don't really care about Sonos Controller showing the disc/set number, but it would be nice to be able to select the album and play the songs in their correct order.
I'm using Sonos Controller for Mac: 8.6