The Never-Before-Released Masters is 1987 compilation album containing unreleased recordings recorded by Motown girl-group The Supremes from 1961 to 1969. It was the second CD release of unreleased recordings by The Supremes, the first being disc two of the 2 disc "25th Anniversary" compilation. Several other unreleased tracks appeared on earlier various artists compilations.
 Several other unreleased tracks appeared on earlier various artists albums.
The compilations may not have been released as albums and could have been just songs. I think that the system has trouble differentiating between the two. 