The following artists made significant vocal contributions to the album, but are generally not considered regular members of the band; therefore, they currently have the "guest" attribute flagged on their performance ARs:
LD Beghtol, Dudley Klute and Shirley Simms.
(applies to all three volumes)
Suboptimal AR credits:
Volume 2, Track 12, "Promises of Eternity": Chris Ewen plays the instruments and provides the backing track. (Currently credit as: guest performed by Chris Ewen.)
'Volume 3, Track 2, "It's a Crime": Chris Ewen plays all instruments and provides the backing track. (Currently credit as: guest performed by Chris Ewen.)
Volume 3, Track 15, "Blue You": Claudia Gonson provides whistling. (Currently credited as: other vocal performed by Claudia Gonson.)