The German soprano Lilli Lehmann once remarked that the singing of all three Brünnhilde roles of Wagner's opera cycle Der Ring des Nibelungen in one evening would be less stressful than the singing of one Norma.
Den tyske sopran Lilli Lehmann fremsatte engang en berømt bemærkning om, at det ville være mindre stresssende at synge alle tre Brünnhilder i Wagners Der Ring des Nibelungen på en aften end at synge én Norma.