Ihsahn (born 1975), born Vegard Sverre Tveitan, is a Norwegian guitar, bass and keyboard player and vocalist. He is best known for his work with Norwegian black metal band Emperor. He played in Peccatum with his wife Ihriel (real name Heidi S. Tveitan) until 2006 and has appeared in Thou Shalt Suffer, Zyklon-B and Hardingrock, and now devotes himself to his solo project, Ihsahn. In very early releases he went by the name Ygg.