Hi, okay using this as an example
https://musicbrainz.org/recording/a65ca6ef-8250-4914-9902-3a667e3a8054
MusicBrainz lets you create a relationship between a Person (Artist) and a Recording with a role, that role maybe a performer like role such as Timothy Mason plays cello or it may be a technical role such as Karl-August Naegler as Recording engineer or Gregor Zielinsky as Balance Engineer.
Now the problem is that MusicBrainz doesnt categorize these roles but the metadata fields used by different aufio formats have different fields for different things, and it does differe between audio formats but with SongKong we provide a set of fields that we can support for all audio fornats. So there is a Performer field that is only intended for musical performers on the track, and there are technical fields such as Producer and Remixer and Engineer. But take the Engineer field as an example that simply lists engineers it cannot capture if Engineer, Recording Engineer or Balance Engineer, we have to do a mapping to decide which type of engineers should be added to the Engineer field and we dont currently include Balance Engineer.
There is also an Involved Person field that can store person and role, but again MusicBrainz can potentially add a huge number of roles, and in the context of music tagging some of these roles such as Legal Representative or Booking are things that are very unlikely to be helpful for tagging., So instead of adding all roles blindly we add a comprehensive subset of the roles.
So in summary maybe we should add Balance Engineer but we dont currently, I dont think we should add all roles blindly.