Internet changed the music industry. At first, sharing systems like Napster allowed people to share any song they had on their computer with millions other people. That new reality changed the music industry’s landscape for good, and many juridical battles followed. However, a biggest change followed a couple of years later. Communities like MySpace started to appear. Strong of millions of regular users, such communities helped garage bands and obscure musicians to create their musical niche: the longtail of the music industry.

This second change is more profound than the first one: now any musician has the possibility to reach their audience by sharing their work on the Web. In the mean time, a free database called MusicBrainz archiving million of between artists, albums and tracks appeared; music suggesting services like Pandora started to appear and Apple started to sell individual tracks at 1$ with iTunes.

At that point, the music industry of the eighties leaded by blockbusters was completely changed.


I am pleased to announce you the publication of a new Music Ontology Specification. I spent the last days writing it having in mind to describe the new MusicBrainz metadatabase structure using RDF and ultimately to write a specification that any music content creator/publisher could use to export the data they are generating.

Please let me know if you find any error in that new ontology, if you have any suggestion to enhance it or if you have any comments.

You can leave comments/suggestions on this blog post or on the related Google Group:

The Music Ontology

The Music Ontology is an attempt to link all the information about musical Artists, Albums and Tracks together: from MusicBrainz to MySpace. The goal is to express all relations between musical information to help people finding anything about music and musicians. It is based around the use of machine readable information provided by any web site or web service on the Web.

Why another music ontology?

Leigh Dodds wrote an ontology based on MusicBrainz about 3 years ago called the MusicBrainz Metadata Vocabulary. At that time, the MusicBrainz database was not as developed as the one available today.

For that reason, I choose to write a new ontology, also based on the MusicBrainz project considering that source of information about music. I developed that new ontology having three goals in mind:

  1. I needed to stay as close as possible to the MusicBrainz database.
  2. I need to reuse the basic principles of the MusicBrainz Metadata Vocabulary.
  3. I need, at the same time, to develop a music ontology that people could use in their system (MySpace, Pandora, blogs, Etc.) and not just in conjunction with the MusicBrainz relational database.

The first goal explains why this new ontology is so influenced by the MusicBrainz database. In fact, most of the classes, properties came from the relations described in the database, and most of the descriptions of these relations came from the wiki of the project.

The second goal explains why the basic classes of the Music Ontology are the same as the one in the MusicBrainz Medata Vocabulary.

The third goal explains why the name and the namespace of the MusicBrainz Metadata Vocabulary have been changed.

What next?

From that point, I will export a RDF version of the MusicBrainz ontology using that new music ontology. Then I’ll index this new RDF data into the triple store, based on Ping the Semantic Web, I talked about a couple of weeks ago (a first version should be released soon by the way).

From that point, people will be able to query the MusicBrainz ontology using the SPARQL endpoint. As I shown in the specification with a couple of SPARQL queries, people will have much more ways to query the database to answer their questions about music things.

More Information

For more information please read the entire Music Ontology Specification.

The ontology has 19 classes and 58 properties.

The namespace of the ontology is and the prefix I suggest to use is “mo”.

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7 thoughts on “The Music Ontology: a new ontology based on the MusicBrainz project

  1. This seems to be good stuff! Cool!

    A minor bug: it seems that the link in the top of the documents links to SIOC, which probably is not what you wanted …

  2. Good effort, BUT the namespace link does NOT return the ontology! Is this intended or is this just birth-pains? 🙂

  3. Hi Mr. Grimnes,

    Hummm, is returning the rdfs file describing the ontology, doesn’t it? At least this is what I get right now 😉

    Could you confirm please? 🙂

    BTW, thanks for your good words, tell me if you find anything else 🙂

    Take care,


  4. Hi Mr. Kopsa,

    Oups, yeah you are right 🙂 I forgot to change that link. In fact I used Uldis’s revision of Danbri’s work (the spec template), so I missed it 🙂

    thanks for reporting it, I will change it this morning.

    Take care,


  5. Yep! It works now – maybe something was slow to propegate, it was 404 earlier today!

  6. I don’t normally comment on ontologies outside the domain I work in (science). However, as both a music fan and a semweb geek I’m keen to see some killer apps in this domain. Unfortunately, I find the MO to be somewhat lacking when I apply the same kind of analysis that one would normally perform on a scientific ontology. See here for details:

    In fairness many of these criticisms can be applied to much of the semantic web. Perhaps you may think that many of my points are not applicable to an ontology like MO which is not intended to have the rigor of a scientific ontology. I would disagree – I have a lot of experience with a variety of ontologies, including ontology content, data and writing applications and I would strongly recommend a more rigorous approach to semantic web resources if these are to be used and trusted more widely outside the current limited range of boutique applications.


  7. Hi Chris,

    Thank you very much for these insighful comments and suggestions about the Music Ontology.

    Please read my comments about this blog post on the Music Ontology mailing list at:

    Thanks for your time and expertise.

    Take care and happy new year,

    Take care,


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