I have several Cher albums in my library. Those two produce an error:
Both contain “All or Nothing” song composed by Paul Barry and Mark Taylor. However, in Roon one compilation (from “The Very Best Of Cher” album) is missing and I am unable to merge them to have working link in album view.
Does Roon use MusicBrainz? I thought it uses AllMusic. Also, I have noticed that I have yet another release. I actually own 2CD set with 19+23 songs. Barcode is 8 25646 08645 0. I wonder how actually compositions work in Roon. Forum pages says it is about composers in credits. But for me it looks like it’s something more as manual editing composers does not fix it.
I can say only what I experienced until now about compositions, but I think I understood them.
If you tag a track with the COMPOSER tag Roon searches into its database and if it finds a composition with the same title and composer(s) of the track you tagged it generates it. The source for Roon database is AllMusic (the composition exists if the track has a composer: see image below) or MusicBrainz (the composition exists if the track is associated to a composition: see the other image below). In case the composition exists both in AllMusic and MusicBrainz I think the AllMusic one is preferred. If MusicBrainz has not a composition associated to a track you can add it in Edit Relationships (that’s what I did with Cher’s compilation album that you requested here).