That there is a “prefer Roon” setting means that the album is identified by Roon.
“Prefer” is not the same as “use my tags exclusively”. It means that if a tag exists in both sources (Roon and file tags), use the one I prefer. If a tag exists in one source only (like possibly the Act tag in Roon only) then it gets used - nothing to prefer here as it is missing in the other source.
See also the hint about Performance/composition munging in Metadata Model:
Maybe you can get what you want for how the album tracks are displayed by making the album unidentifed in Roon but this may yield other, possibly unwanted, results (like for example: the performance becomes unrecognized [not listed under performances for that composition]).
Then use that button, keep telling Roon that “None of these look right” and you will end-up with a now unidentified album.
Agreed that it doesn’t have more than one act but the display of “Act 1” is just explicitly stating that. It’s not a false information, it just looks odd in some peoples eyes.
To provide another thought path: As Das Rheingold is part of the Der Ring des Nibelungen cycle of works and those other works do have acts, someone might have added the “Act 1” tag just for the sake of consistency among the different works of the complete cycle.
The Ring Cycle is a festival play with three operas & a prelude evening, Das Rheingold. Granted it’s as long as most normal operas, but this is Wagner we’re talking about. It doesn’t have acts, plain & simple. Act I will not be found on any release in any format. It is not a one act opera, it is a prelude.
Sorry for sounding like “that guy”. I’m nice really.
Thanks Blackjack, for the unidentifying technique.
Thanks, Mike_O_Neill, that sounds well advanced for a novice like me, but I’ll read it ten times & see if I can make it work.