Allow byArtist to accept a Person as well as a MusicGroup

[vholland]

http://schema.org/MusicAlbum and http://schema.org/MusicRecording use http://schema.org/byArtist to designate the artist credited with an album. Currently, the only acceptable type is http://schema.org/MusicGroup.

While MusicGroup's description says it can be used for individual artists, it is a subtype of http://schema.org/PerformingGroup, which does not.

Given it makes distinguishing groups from individuals, the simplest thing would be to expand the range of byArtist to accept http://schema.org/Person as well.

[thadguidry]

@vholland so we are saying that our Group Types should be considered restricted for use of MORE THAN 1 PERSON ? I'm fine with that restriction.

In some databases, a Music Group could be used for either 1 person or a group. We might want to mention something about our restriction in our MusicGroup and PerformingGroup definitions ?

[vholland]

@thadguidry Yes, that was my thought. Both definitions would need updating.

[danbri]

SGTM. Can you make a PR (with a line giving docs/releases.html text ideally:)

[vholland]

I will tomorrow. I was being lazy and wanted to make sure there were no shouts of "For the love of all that is good in data modeling, NOOOOO!" before I did any work.

[vholland]

When I said tomorrow, I must have meant in the metaphorical sense. Anyway, see PR #2038

[RichardWallis]

Implemented in release 3.5