Choir and Orchestra of the Roman Radio. Dir. Riccardo Muti. Montserrat Caballe (Agnes of Hohenstaufen, wife of Henry of Brunswick), Giangiacomo Guelfi (Henry of Brunswick, son of Henry the Lion), Giampaolo Corradi (Philip of Hohenstaufen, brother of the king), Sesto Bruscantini (Duke of Burgundy, King of France), Walter Alberti (Henry the Lion, Duke of Saxony, representative of the Guelph dynasty), Bruno Prevedi (Emperor Henry VI), Antonietta Stella (Irmengarda, mother of Agnes, widow of Konra