MusicBrainz Identifier

One of MusicBrainz' most fundamental purposes is to enable people and computers to have meaningful conversations about music; however, to truly have a meaningful conversation all involved parties must be able to reliably and unambiguously identify what is being discussed. To this end, MusicBrainz assigns a unique MusicBrainz Identifier (MBID), to all artists, release groups, releases, tracks, and labels in the MusicBrainz Database, and uses these MBIDs as a universal lingua franca for music. These MBIDs, aside from being unique to the specific entity it is associated with, are also a permanent identifier for that entity for as long the entity exists.

Definition

A MusicBrainz Identifier is an absolute Uniform Resource Identifier.

This URI takes the form http://musicbrainz.org/<ENTITY>/<UUID>, where <ENTITY> refers to one of the previously mentioned musical entities (artist, release-group, release, track, or label), and <UUID> refers to a Universally Unique Identifier assigned to that entity.

Examples

• http://musicbrainz.org/artist/53b106e7-0cc6-42cc-ac95-ed8d30a3a98e is the MBID for the artist John Williams.
• http://musicbrainz.org/release/44b7cab1-0ce1-404e-9089-b458eb3fa530 is the MBID for the release Sgt. Pepper's Lonely Hearts Club Band.
• http://musicbrainz.org/track/62c2e20a-559e-422f-a44c-9afa7882f0c4 is the MBID for the track Enter Sandman.

Using MusicBrainz Identifiers

In situations where the context is clear (such as within the MusicBrainz namespace, or file metadata) the above absolute URIs can be converted into their relative form. These relative URIs consist of just the <UUID> portion of the MBID.

Thus, the above MBIDs in their relative form produce:

• 53b106e7-0cc6-42cc-ac95-ed8d30a3a98e is the relative MBID for the artist John Williams.
• 44b7cab1-0ce1-404e-9089-b458eb3fa530 is the relative MBID for the release Sgt. Pepper's Lonely Hearts Club Band.
• 62c2e20a-559e-422f-a44c-9afa7882f0c4 is the relative MBID for the track Enter Sandman.

Using a relative MBID is OK as long as you qualify it or it has been given context. For example, relative MBIDs are used on entity pages.

When the MBID is listed in relative form it can be converted back to its absolute form by prepending http://musicbrainz.org/<ENTITY>/ to it.

Entity pages on the website

The URI that makes up an MBID is not the same as the URL that is required to visit an entity's page on the MusicBrainz website.

To get the valid web address add .html to the end of an absolute MBID like so:

• http://musicbrainz.org/artist/53b106e7-0cc6-42cc-ac95-ed8d30a3a98e.html is the URL for John Williams' artist page.
• http://musicbrainz.org/release/44b7cab1-0ce1-404e-9089-b458eb3fa530.html is the URL for Sgt. Pepper's Lonely Hearts Club Band's release page.
• http://musicbrainz.org/track/62c2e20a-559e-422f-a44c-9afa7882f0c4.html is the URL for Enter Sandman's track page.

The upcoming server release, scheduled for release in 2010, will address this issue and the canonical MBID will resolve to the appropriate page.

Tagging applications

MBIDs play an important role when tagging music files with metadata with any of the various MusicBrainz Taggers.

When writing metadata, a MusicBrainz enabled tagger application will write several different relative MBIDs to each file, one for each of the following:

• the track itself
• the track artist
• the release
• the release artist

See MusicBrainz Tag for more detailed information.

See also

There are several other identifiers that MusicBrainz uses:

• Disc ID: An ID calculated from the TOC of a CD.
• PUID: The IDs used in the proprietary MusicDNS audio fingerprinting system operated by MusicIP.
• Barcode: Machine-readable numbers used as stock control mechanisms by retailers.
• ISRC: The International Standard Recording Code, an identification system for audio and music video recordings.