Defintion of a Work
My current attempt at defining a work:
A Work is a new musical creation or a creative combination of existing musical creations. Works can be performed and recorded to create recordings or recordings can be creatively combined to create new recordings.
By allowing a wider definition of a Work we can capture more information about the Work. For instance, if a compilation of music is considered a Work, then the release level information/ARs can capture the information about the recordings contained in the compilation and the Work level information/ARs can capture the information about the compilation itself.
Works for Compilations, DJ-Mixes and Mash-ups
Artist Credits for Works
A work artist_credit is used to indicate the artist(s) commonly associated with a work. The actual composer of the work is defined via an artist-work AR.
ISWCs for Works
In most cases, ISWCs should be attached to only one Work. Rare cases may require an ISWC to be attached to multiple works.
Tricky things to consider
- ISWCs attached to multiple works: http://chatlogs.musicbrainz.org/musicbrainz-devel/2010/2010-09/2010-09-13.html#T19-31-11-56868
- Work artists: http://lists.musicbrainz.org/pipermail/musicbrainz-style/2010-April/009355.html
- ARs to the medium level: http://jira.musicbrainz.org/browse/MBS-802
- Fuzzy ARs: http://chatlogs.musicbrainz.org/musicbrainz-devel/2010/2010-09/2010-09-13.html#T20-18-59-315250