I didn’t want to make a new thread for this, I think it fits here (edit by @reosarevok: I think a new thread is better actually so split 
):
What to do about used-to-be-groups?
For example:
Currently there’s no way to use multiple types for different time spans. So I guess both cases should be updated to ‘person’ and the historic group info should be moved to annotation, right?
Both of those groups were around for a decent length of time. So I would say they are now a “group” with a single member. All the other full time members have now left, but I assume these artists are now using other musicians on a temporary basis.
I don’t think downgrading previous band members into an annotation makes sense. They were there as full members during the bands main years.
Yeah, but that’s a trade-off too.
Also, both examples are producers/djs. In this area groups are more like long-term collaborations rather than bands per se. It usually boils down to sending production files back and forth and teaming up for occasional live acts/dj sets. Then again, that’s not a defined thing, just the general idea.
My point is that ideally such cases would include both types to be completely accurate. Alas, for now it’s impossible.
So, you know, at this point calling “Ancient Methods” or “Radial” a one member group is just as inaccurate as categorising it as a person. Because for the last couple of years (and releases, and live acts) both have been functioning as performance aliases for solo artists. Just like we don’t call Machinedrum a single member band of Travis Stewart or Fever Ray a group centred around Karin Dreijer.
It is the classic problem of trying to jam things into categories. There are always edge cases. Not everyone fits into a neat little box 
In some cases the specific artist is the name on the box, and that artist doesn’t acknowledge the names of his backing musicians. He just swaps one guitarist for another and sees the main work as “his”. To me, that is a case where clearly it is just a single artist and not a group.
With your examples we have an artist who performs under a different title - and brings in collaborations with other artists. As far as I can see it is important to the artist for those collaborators to get proper credit.
It is not really a “group”, but it is also not an “individual”. It looks to me like “Ancient Methods” is used as a title for his collaborative projects. This is why I think it is more comfortable as a “group” with changing members instead of just an “individual artist”.
Just my opinion… Maybe a few other people will chip in their thoughts.
I clearly prefer group, if it was correct to call the artist a group at some time.
If there were other members, the information, that they were members doesn’t become
incorrect when all but one leaves and should be kept as "member of … from … until … " relationship.
A group with only one member left is less problematic - if there is any problem at all - than
a person having members.
Another case would be, if the artist should never have been called “group”, but was a single
artist with other artists supporting him on a regular/quite permanent basis.
There is a relationship for this case, too. Relationships are clearly preferable to annotations.
What about creating two entities named Ancient Methods, one for the group and one for the person? Active dates could indicate when the group stopped performing/recording and (if we had active dates for solo artist) when the solo project started.
I personally don’t have an issue with the single-member-group approach, though. It seems like if it was a group at one point, and the remaining “member” is continuing to use the same name, they are claiming a certain continuity with the group.
I’d also vote for keeping group, just with only one linked member that doesn’t have an end date set. It’s the most flexible option, and keeps one entity even if the current solo artist decides to add a new partner next year. It also arguably retains more information.
If you feel absolutely strongly about the entity type, then I guess you can just add a new entity with the disambigs set to “group, yyyy-yyy” and “solo project, yyyy-”, respectively.
It may make sense to make this an explicit style guideline either way, so that it’s handled consistently acrss the database. @reosarevok
maybe i have a bit different question here about the artist entry Kawabata Makoto & The Mothers of Invasion (MB (misspelled artist name…) / Discogs)
on his Bandcamp release pages (1 / 2) Kawabata states, that the releases are by a solo project of his named “The Mothers of Invasion” with changing lineups / backing bands (?).
how should “Kawabata Makoto & The Mothers of Inasion” be reflected here?
i am thinking right now as of “Kawabata Makoto & The Mothers of Invasion” as an person-alias of Kawabata Makoto because there probably won’t be a consistent membership lineup.
ideas? 