MusicBrainz Identifier

One of MusicBrainz' aims is to be the universal lingua franca for music by providing a reliable and unambiguous form of music identification; this music identification is performed through the use of MusicBrainz Identifiers (MBIDs).

In a nutshell, an MBID is a 36 character Universally Unique Identifier that is permanently assigned to each entity in the database, i.e. artists, release groups, releases, recordings, works, labels, areas, places and URLs. MBIDs are also assigned to Tracks, though tracks do not share many other properties of entities. For example, the artist Queen has an artist MBID of 0383dadf-2a4e-4d10-a46a-e9e041da8eb3, and their song Bohemian Rhapsody has a recording MBID of ebf79ba5-085e-48d2-9eb8-2d992fbf0f6d.

An entity can have more than one MBID. When an entity is merged into another, its MBIDs redirect to the other entity.

Using MBIDs for disambiguation

MBIDs are used to disambiguate between entities that share the same name in the MusicBrainz Database.

For example, there are two popular artists with the name "John Williams":

John Williams, the soundtrack composer and conductor, has an artist MBID of 53b106e7-0cc6-42cc-ac95-ed8d30a3a98e
John Williams, the classical guitar player, has an artist MBID of 8b8a38a9-a290-4560-84f6-3d4466e8d791

And there are two different singles titled "99 Red Balloons":

99 Red Balloons, the original by Nena, has a release MBID of 189002e7-3285-4e2e-92a3-7f6c30d407a2
99 Red Balloons, the cover by Goldfinger, has a release MBID of c9f91cdc-984e-4303-9a51-4ac0dfa2348f

Using MBIDs in applications

MBIDs play an important role when managing a digital music collection and there are several applications that are MusicBrainz enabled.

Taggers

Multiple MBIDs may be written to a file by a MusicBrainz enabled tagger application. They are commonly used to identify:

the recording itself
the release
the label
the track artist
the release artist

For more information, see the tag documentation and the tag mappings of the MusicBrainz Picard tagger.

Music players

Music player applications can take advantage of a file that has been tagged with MBIDs to do things such as:

query the MusicBrainz Database for further information about the file or related entities
reliably search for related files based on a unique string, instead of by potentially ambiguous strings such as artist name or release title

Flickr

See Flickr Machine Tag for information about adding MBIDs to photos on Flickr.

Uniform Resource Identifier

URIs can be constructed by prefixing the MBID with the address of the MusicBrainz server and the entity type, for example Queen's URI becomes http://musicbrainz.org/artist/0383dadf-2a4e-4d10-a46a-e9e041da8eb3, and Bohemian Rhapsody's URI becomes http://musicbrainz.org/recording/ebf79ba5-085e-48d2-9eb8-2d992fbf0f6d.