Un-Merging Compositions in an Identified Album

Is there anyway of un-merging a composition in an identified album?

The Harmonia Mundi Cornerstones of Sacred Music Box set (30CD) has 4 Stabat Mater’s by four different composers spread over disks 20 and 21. These are Pergolesi, Boccherini, Vivaldi and Rossini.

Roon is identifying the Rossini Stabat Mater as a Pergolesi Statbat Mater and I cannot find a way of telling Roon otherwise. In fact it is all quite a mess as you can see from this screen shot each ‘part’ seems to be a who’s who of every composer who ever wrote a Stabat mater:

I have tried:

  1. Removing unwanted composer credits
  2. Making sure the canonical title of the Rossini Stabat Mater is different from the Pergolesi Stabat Mater.

But this assignment seems to be at the ‘composition’ level. I don’t want to ‘unidentify’ the album as it is a 30CD box set and mostly Roon has got it right and I would rather not go through a tedious manual grooming excercise of a very complex ancient music box set.

Is it possible to just remove this Rossini Stabat Mataer from the Pergolesi composition group so that I can merge it with the Rossini Stabat Mater group?

You could try setting COMPOSITION and MOVEMENT tags on just this set of problematic tracks. This worked for me on similar issues I had in the past.

Thanks, already tried that but I think it is designed for unidentified content. I have had a similar experience as you with with identified content. Sometimes it works but it is hit and miss and in this case no joy. It is almost as if Roon is just overwriting anything I try to do. Is this just a case where these tracks have been misidentified by rovi/etc.?

Hi @Tony_Casey. The COMPOSITION and MOVEMENT tags now work for identified content, so you should be able to clean this up. You may also need to remove certain composer credits.

The problem here is some awful MusicBrainz metadata:


Although the artist (= composer) is correct (according to the MusicBrainz classical style guidelines, not Roon’s), you can see that the recordings are an inconsistent mis-mash of parts from different composers’ compositions.

As an aside, these MusicBrainz metadata are for 29 discs. Which one is missing?

@mike @brian FYI

@Tony_Casey I’ve made the edits in MusicBrainz, which will take a week to commit. Then it will take up to a week to deploy to your library. If you are happy to wait, perhaps you would get back to me in a couple of weeks to let me know if it’s fixed things?

Wow @joel ! I could never imagine the MusikBrainz data would be that far off. Thanks for the fix. I’ll keep an eye on it and confirm when the change percolates through.

The missing 30th disk is documentation / jpg’s. So nothing to worry about although I must admit it confused me as well.

I have been working my way through that box set. So unfortunately I am coming across other problems. I can see MusicBrainz is using a WORK: PART convention for track title’s but in many cases in this box set I cannot force the grouping of part’s. The worse offender so far is disc’s 11 and 12 which is a complete Scarlatti oratorio. I cannot get the part’s to group even if I manually tag WORK/PART. Roon seems to acknowledge the change and the WORK/PART structure momentarily flickers on the screen. But it doesn’t stick and whatever I do I end up with this:

There was (is?) a thread for ‘artist equivalence’ issues. Is there somewhere to systematically report these miss-identified multi-part compositions?

Can you show me your file tags for those Scarlatti tracks?

@joel I don’t know how to show the tags in roon. Where is that? But this is how they look in mp3tag

As you can see, I have manually populated more or less everything. This is only because roon was having problems. Mostly I just prefer Roon to do it. Also, as in my previous comment I find that Roon’s handling of WORK/PART for identified albums is very hit and miss. This is a case where Roon seems to ignores my WORK/PART tagging, although I can see that Roon does momentarily acknowldge the edits (the changed structure flashes on the screen) but it does not stick and Roon reverts.

Probably, because I am going through a massive conversion exercise I am coming across other issue that make manual grooming difficult. For example, I often want to manually merge artist equivalents to tidy things up, but this can be difficult/impossible under several use cases where it is not possible to filter the equivalents on the artist merge page in the first place. I will raise a different thread as it is a separate issue.


Hi Tony, I think you are just missing one settings change to make this work. Here’s an example: The Four Seasons split into four individual concerti.


Go to Settings -> Library Settings

Select “Prefer File” for Composition/Part Grouping:


Hi @joel,

I was aware of that option but I didn’t understand what it did. Most of the time I certainly do not want roon to prefer local composition grouping as it won’t be right unless I have manually gone to the trouble of populating the WORK/PART tags.

I should have asked first but is that what roon does? Only overwrite roon composition grouping if the WORK/PAT tags are populated? I hope that is the case as I was too quick off the mark and applied the preference and I can see it is going to take roon quite a while to work through my library.

Two things:

  1. Yes, it only affects things when you have WORK/PART tags.
  2. It’s not a permanent, one-way change. The Roon Core actually retains all of the Roon metadata and you can easily go back to preferring Roon metadata.

Thanks @joel, That has worked really well. Didn’t take as long as I thought. Maybe I am not the only one who didn’t understand that option. Very useful.


My bad: you can select “Prefer File” for Composition/Part Grouping on a per album basis.

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Yes, Indeed. You only need to clean up the few albums which need it.

The problem with this per album feature is that Roon does not tell you which setting is currently active for a given album,so you never know for sure after you changed it if Roon has acknowledged the change or not.I think this has been hinted at before. Do you think this could be fixed ?