The Tolkien Ensemble published four CDs from 1997 to 2005 with the aim to create "the world's first complete musical interpretation of the poems and songs from The Lord of the Rings". The project was given approval by both the Tolkien family and Harper Collins Publishers. Queen Margarethe II of Denmark gave permission to use her illustrations in the CD layout. Permanent members of the ensemble are Caspar Reiff and Peter Hall (composition, singing and guitar), Signe Asmussen (singing), Öyvind Ougaard (accordion), Katja Nielsen (double-bass), and Morten Ryelund Sørensen (conductor and violin).