As you may know, in our Next Generation Schema release we are including support for musical Works. Our definition of a Work is a musical composition that will at some point be performed and possibly recorded, in which case it will become a Recording. In the current MusicBrainz implementation we do not have the concept of a Work and a lot of the Advanced Relationships (ARs) we have are muddled between the concept of a Work or a Recording.
This left us with the tricky task of reviewing all track level ARs and prying apart which ARs should be moved to Works and which ones to Recording. Or both! To accomplish this task, Brianfreud had compiled a list of open issues, which Ian McEwen has adopted and nutured. Today we convened an IRC meeting with Nikki, Pete Marsh from the BBC, Ian and myself. If you’re interested in how we reached the decisions we did, please take a look at the chatlog.
Our decisions have been captured in this wiki page — please take a look at it and see if we’ve missed anything or if there is anything you disagree with. If we do not hear any feedback on this topic, we will change our NGS data conversion script to convert the data as decided in this page.
Thanks to Ian, Pete and Nikki for your help in this meeting! And big thanks also go to Murdos for all of your help in steering me towards getting all Works related issues on to the table!
MetaBrainz Blog 
I wonder whether “Producer” is at the right level. This term means different things across genres; for electronic, lots of hip hop, and quite a bit of pop now, the producer is often the main composer/writer and the work would not happen without them. Rappers and vocalists get writing credits, but can often have limited involvement in the beat/music. Of course the producers are usually credited as composers/writers as well, but the term is used a bit differently.
voice: Thats an interesting perspective with rather complicated implications for us. I suppose we need to capture the metadata as the industry (ab)uses it, so we need to be flexible. Would setting this AR type to Both fix this problem in your opinion?
It might fix it, but it also might open a world of editing confusion that’s not worth the hassle! I’d be interested in whether my perspective on Producers is agreed upon by others who’ve ARed a lot in this area – alphaseven, mfmeulenbelt, Time Dilation come to mind. Come to think of it, the same could be said of producers with much of 50s-70s US soul/funk, couldn’t it? I guess what I’m looking for is to avoid having to duplicate this at the recording level, but then again if there’s only really ever one recording of such tracks, maybe it doesn’t matter so much. I dunno, I’m still not entirely clear on the relationship between the two terms. Obviously the blog isn’t the best place to discuss such things. Do I have to look at the style mailing list again? 🙂
You might want to take a look at FRBR (functional requirements for bibliographic records: http://www.ifla.org/en/publications/functional-requirements-for-bibliographic-records). This model is integrated in the newest cataloging methodologies. See RDA (http://www.rdatoolkit.org/constituencyreview/). From quick perusal, I think you have about the same ideas.
Basically there are four levels of entities: work (Beethoven 9th), expression (recording by such Orchestra), manifestation (tracks 1-4 of the CD published by X), and item (my copy of it). RDA describes some general relations (including relations at the same level, e.g. work-work, “musical arrangement of”).
Separately the relator code list for MARC might be of interest (albeit a bit general): http://www.loc.gov/marc/relators/relacode.html
That definition of “Work” sounds funky to me… The definition of a work given – “Our definition of a Work is a musical composition that will at some point be performed and possibly recorded, in which case it will become a Recording” – implies that known but lost compositions are invalid for Works. It also kind of makes it sound like Works are a transitional entity that ceases to exist once a recording exists, rather than being the entity representing the “composition” layer which exists above almost all recordings…
@voiceinsideyou: re. “the producer is often the main composer/writer and the work would not happen without them” – it shouldn’t really matter, whether a person also represents two roles in the production process – then this person should be associated with these two roles.
@alias: There is currently a project (http://wiki.musicbrainz.org/LinkedBrainz http://linkedbrainz.c4dmpresents.org/) going on, where a mapping from the MusicBrainz NGS schema to the Music Ontology (http://musicontology.com/) should be the output. The Music Ontology is a music domain specific ontology, which is build on top of the 4 levels of the FRBR Vocabulary. That means we have there already these levels for music specific concepts.