Or, to be more precise, under what circumstances can a work be a part of more than one work?
I have come across several instances where a work has been listed as a ‘part’ of another work where the relationship hadn’t struck me as being “proper”. The one that struck me most recently was the soundtrack Neon Genesis Evangelion which listed several original Bach works among its parts (in one case duplicated by an arrangement). I deleted these relationships, but haven’t fixed it with alternatives (at least, not yet…) as the matter got me thinking about the whole issue of claiming an original work to be part of some other later ‘work’ just because the ‘composer’ (compiler?) chose to include it. This strikes me as wrong and potentially chaotic, with many famous pieces being listed as “part of” lots of derivative works as well as the the original work.
I searched in vain for something in the style guidelines - perhaps I missed it?
One obvious approach is to use an “arrangement” relationship, but what if the soundtrack or whatever just used the original composition?
On further investigation, there are more subtle instances. For example, Holst’s ‘Planet Suite’ has two MB works: The Planets, op. 32 (original version) and The Planets Suite for Orchestra, op. 32 (with “Pluto” by Colin Matthews). At least the latter has the “version of” relationship, but surely any of the original ‘planets’ should only be shown as a part of the original?
Perhaps there is something missing in the relationship structure that leads to this state of affairs? In other words, should there not be a “used in” relationship (reverse = “uses”) where the other work is not the composition of which it is a part but simply quotes it in full or part?
Any thoughts before I go mindlessly hacking more relationships ?
EDIT: Looking into Neon Genesis Evangelion a bit more, I have no regrets about removing the relationships. It seems that the list of “parts” is a general mish-mash of stuff that appears on various media. The classical works seem to be simply recordings, not part of separate works, from what I can see. The more general question remains, however. Not wishing to denigrate Colin Matthews’ addition, but what’s to stop me adding another random rock to the suite and listing a new work, calling it “The Planets Suite, op. 32 (with two tings on a triangle for Astraea by MetaTunes)”?