Release Group / Type


The type of a release group describes what kind of release group it is. It is divided in two: a release group can have a "main" type and an unspecified number of extra types.

Primary types


An album, perhaps better defined as a "Long Play" (LP) release, generally consists of previously unreleased material (unless this type is combined with secondary types which change that, such as "Compilation").


A single has different definitions depending on the market it is released for.

There are other variations of the single called a "split single" where songs by two different artists are released on the one disc, typically vinyl. The term "B-Side" comes from the era when singles were released on 7 inch (or sometimes 12 inch) vinyl with a song on each side, and so side A is the track that the single is named for, and the other side - side B - would contain a bonus song, or sometimes even the same song.


An EP is a so-called "Extended Play" release and often contains the letters EP in the title. Generally an EP will be shorter than a full length release (an LP or "Long Play") and the tracks are usually exclusive to the EP, in other words the tracks don't come from a previously issued release. EP is fairly difficult to define; usually it should only be assumed that a release is an EP if the artist defines it as such.


An episodic release that was originally broadcast via radio, television, or the Internet, including podcasts.


Any release that does not fit or can't decisively be placed in any of the categories above.

Secondary types


A compilation, for the purposes of the MusicBrainz database, covers the following types of releases:

The MusicBrainz project does not generally consider the following to be compilations:

Compilation should be used in addition to, not instead of, other types: for example, a various artists soundtrack using pre-released music should be marked as both a soundtrack and a compilation. As a general rule, always select every secondary type that applies.


A soundtrack is the musical score to a movie, TV series, stage show, computer game etc. In the specific cases of computer games, a game CD with audio tracks should be classified as a soundtrack: the musical properties of the CD are more interesting to MusicBrainz than the data properties.


Non-music spoken word releases.


An interview release contains an interview, generally with an artist.


An audiobook is a book read by a narrator without music.


A release that was recorded live.


A release that primarily contains remixed material.


A DJ-mix is a sequence of several recordings played one after the other, each one modified so that they blend together into a continuous flow of music. A DJ mix release requires that the recordings be modified in some manner, and the DJ who does this modification is usually (although not always) credited in a fairly prominent way.


Promotional in nature (but not necessarily free), mixtapes and street albums are often released by artists to promote new artists, or upcoming studio albums by prominent artists. They are also sometimes used to keep fans' attention between studio releases and are most common in rap & hip hop genres. They are often not sanctioned by the artist's label, may lack proper sample or song clearances and vary widely in production and recording quality. While mixtapes are generally DJ-mixed, they are distinct from commercial DJ mixes (which are usually deemed compilations) and are defined by having a significant proportion of new material, including original production or original vocals over top of other artists' instrumentals. They are distinct from demos in that they are designed for release directly to the public and fans; not to labels.