Release Group

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Revision as of 12:19, 28 May 2009 by Atedos (talk | contribs) (FAQs: As discussed on Talk page.)


Status: This is proposed style for a recently released feature (24 May 2009), currently under development. It is not yet official.


A Release Group is a MusicBrainz concept introduced in May 2009 used to group several different releases into a single logical entity. Every release belongs to one, and only one release group.

Both release groups and releases are "albums" in a general sense, but with a slight difference: a release is something you can buy as media, e.g. a CD, a vinyl record etc. on its own, while a release group embraces the concept of an album -- it doesn't matter how many CDs or editions/versions it had. When an artist tells you "We've released our new album", they're talking about a release group. When his publisher says "This new album gets released next week in Japan and next month in Europe", they're talking about the different releases that belong in the release group that the artist told you about.

MusicBrainz automatically considers every release in the database to be part of a release group, even if this group only contains the one release. As an editor you don't have to worry about creating release groups, you will only need to merge existing ones.

There are a number of situations in which merging releases groups is appropriate. All of the following can be part of a single release group:

Regular releases
Since every release is inside a release group, some release groups have only a single release.
International release variations
Releases are often released with different tracklists in different markets, some may even have additional bonus discs. Due to WhatDefinesAUniqueRelease these would be separate releases at MusicBrainz, but should be merged together into the same release group.
Deluxe/limited editions and reissues/remasters
Just like above, a "special" edition of an album, a reissue of an album, or a remaster, should all be part of the same release group.
Promotional and bootleg versions
Promotional and bootleg versions of albums, singles etc should be in the same release group as the regular official release.
Multi-disc releases
Each disc in a multi-disc release at MusicBrainz is a separate release (named according to disc number style), but all discs should be part of the same release group.
Box sets
A special case of the above; each disc in a box set would normally be part of the same release group.
Transliterated or translated pseudo-releases should be part of the same release group as the official release.


When Not to Group Releases together

There are a number of cases where it is not appropriate for releases to be part of the same group:

  • Different bootleg recordings of a live show, e.g. bootleg 1 and bootleg 2 of a 1970 Pink Floyd concert in San Francisco.
  • If the individual discs of a re-released Box Set have not been duplicated, due to the rules outlined at "What Defines A Unique Release", each disc in that set should not be grouped together as per the normal box set rules noted above.


Please only list answered questions below, if you would like to ask a question feel free to come on IRC, use the mailing list, or add a note to the discussion page.

Should a "2 in 1" release group be merged into one of the two associated releases groups?

No, it should form its own third release group because it's a separate album/single/etc. e.g. ABBA's "Waterloo / Voulez-Vous" should not be merged into "Waterloo" or "Voulez-Vous".

Use of Attributes


The title of a release group should be the title of its individual releases, removing Extra Title Information added due to Disc Number Style, Volume Number Style etc.


The types of a release group are the same as those possible for Release Type and should normally be the same as all of the releases in that group. This may not always be the case. It is OK for a bonus disc EP, remix, live disc etc to be inside the same "Album" release group as the accompanying album disc.