If with the default options SongKong is incorrectly marking some releases as Classical when they should not be we can prevent this permanently by modifying the Not Classical Release Group or Nor Classical Release list in Preferences
The classical identification algorithm uses a number of lists that can be modified to effect the algorithm.
For example often classical releases added to MusicBrainz have the composer or conductor added to the artist fields but no relationships are added to indicate that they were a composer or conductor. But the classical people list contains a list of known classical composers and conductors, so if a release contains people from this list this is a strong indication that the release is a classical release and we should set the is_classical flag and apply the classical options.
These list can also be modified in Preferences, the same list is used for all profiles.