Just getting back to this after a break. I would appreciate some views on the best way of determining movement numbers etc. I took a look at @outsidecontext’s plugin (Work & Movements - “W&M” hereafter) and compared it with mine (Classical Extras - “CE”). There are some similarities and differences and neither is completely ideal.
Similar - Both number the movement within the context of its immediate parent. Thus if the work has more than two levels (I will use Petrushka - https://musicbrainz.org/work/57deae1f-4fb3-40c3-aa4f-3167ea0e806a as an example throughout), Tableau II is numbered as part of the whole work, whereas the parts of Tableau I are numbered as part of Tableau I.
Differences - W&M gets its number from the ordering within the parent-work relationship, whereas CE gets its number from the sequence within the actual release (so if a movement is missing on a release, the number sequence in CE will ignore it, whereas W&M will have a gap in the number sequence)
The consequence of this is that for a release that has all the parts of Petrushka as separate tracks, the movements will be numbered as follows:
W&M: 1,2,3,2,1,2,3,1,2,3,4,5,6,7,8,9,10
CE: 1,2,3,4,1,2,3,1,2,3,4,5,6,7,8,9,10
The difference is that in CE, Tableau II gets numbered as being the 4th movement within the sequence of Petrushka tracks.
If some of the tracks combine parts, then the differences are greater: e.g. for release https://musicbrainz.org/release/a94cab1b-4cac-41f1-82e7-990d2f151613 the numbers will be
W&M: 1,3,2,1,3,1,2,3,4,5,6,7,8,9,10
CE: 1,2,3,1,2,1,2,3,4,5,6,7,8,9,10
In W&M, movement 2 of Tableau I is omitted (it is actually on the same track as movement 1). CE gets round this, but only because it has a different concept of movement number.
W&M does not give movement totals. The next release of CE will do, but again using the same context (i.e. immediate parent and only movements which are tracks on the release).
Another approach would be to number the movements within the context of the overall parent, so Petrushka would go 1-17 for the whole work on separate tracks. (but see edit note)
I have no great preference for any method at the moment (I don’t use it myself as I prefer to use the labels that are already there), but would appreciate thoughts as I am about to do a new release.
EDIT: There is a disadvantage of the “overall parent approach” as ceratin works might get counter-intuitive numbering - e.g. Vivaldi’s L’estro armonico (https://musicbrainz.org/work/161dd98a-9b6b-46b1-863b-1899af0d06f9) might mean all the parts of each concerto get treated as part of one sequence (avoidable if the numbering is only applied to parts defined as “movements” and not as “parts of collection” - provided that metadata is present).
Also, I should add that I would ideally like to adopt a consistent approach with W&M on this, as I think that is less confusing for everyone.