Adiemus consists of the Welsh composer Karl Jenkins and his Finnish "Adiemus Singers".
The session singer Miriam Stockley performed the vocal parts on the first four albums. Additional vocals were provided by Mary Carewe on all but Dances of Time, which saw the introduction of the Finnish Adiemus Singers (who would later reappear on Vocalise). Extra vocals and the chorus effects were created by overdubbing multitracked recordings of the singers (in some cases up to forty times) and varying the speed of the tape. Read more on Last.fm