Do we consider it mandatory to create a separate work for the original poem, or is simply adding the poem’s author as a lyricist of the derivative song sufficient? I think it’s nice to have the relationship to the original poem, but OTOH MusicBrainz is a music database, not a poetry database.
Also, is it correct that the author of the poem is related to both the original poem (as writer) and to the derivative song (as lyricist)?
I would create it as a work, if you want to store that relationship, and not worry too much. Link it to the BookBrainz page for the poem if pthere is one (maybe eventually we will have more robust cross-service relationships for this kind of thing ).
I personally don’t think anything is mandatory - up to you!
Nothing is mandatory but personally if I knew some work was based on a particular poem I would always add both works (assuming neither existed to begin with).
This is because if someone else created a different song based on the same poem we’d want the works linked together, and the way to do that is through the common base work.
This one is probably more of a case-by-case judgement call. For songs based on poems, lyrics are not always exactly the same as the original work, so different credits may be appropriate.
This looks like a good reason to add poems as separate works.
Yes, if the lyrics are somehow changed then I agree that we need to credit another artist (and we have “additional lyricist” attribute for that).
But what I am concerned about is duplication of information in the database. In the example from my first post, the same artist (H.P. Lovecraft) is linked to both the original poem, and to the derivative song (and this linking doesn’t happen automatically - an editor must add the relationship twice).
If this relationship is not added to the song, then it will not show up on the page of a recording linked to a song, so that’s a good reason to add it IMO. But adding the same relationship to the song is data duplication.
This is an instance of general problem which occurs which occurs with all kinds of related entities in MB.
For example most performer credits on minor edits of a recording typically would be the same, as would composer credits on translated versions of a song, dates on various recording relationships, etc.
Sometimes you just have to add duplicate information. I’d duplicate the lyricist credit if appropriate: this gives more specific information than just the “based on” relation does and as you say, it is necessary to get the credit showing up on tracks / recordings (both in the website and Picard).
But there’s no need to go overboard either. For the other extreme, I suspect it would very rarely make sense to duplicate URL relations from the poem (if any) to the song.
I don’t think we have any actual style guidelines about this, it’s up to your best judgement
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