In some cases, a Release or Track is performed by more than one Artist, one of them being the PrimaryArtist - others then are called secondary artists.
s (which are related through a CoreRelationship), secondary artists' links to a Release or Track are created through AdvancedRelationships.
There are several different types of such "roles", or ways to relate an Artist to a Release or Track: for an exhaustive list, you may consult either ReleaseArtistRelationship
s or ArtistTrackRelationship
Note that you may use additional AdvancedRelationships for the PrimaryArtist as well, as to describe more precisely what was exactly the artist contribution.
Usually, secondary artists are given credits either on the front sleeve of the release (possibly using a smaller or different font to differentiate them from the PrimaryArtist), or more generally inside the leaflet along with other details about the recording. In some (rare) cases, the release leaflet doesn't mention them at all, and their contribution is only documented in external resources like discography oriented websites, or books.
For the specific cases of secondary artists credited as "featuring", you should read FeaturingArtist and FeaturingArtistStyle.