Vegard Sverre Tveitan, better known by his stage name Ihsahn, is a Norwegian musician, singer, songwriter, record producer, and composer who is best known for his work with the black metal band Emperor. Tveitan is also a founding member of Thou Shalt Suffer, where he played guitar and keyboard in addition to vocal duties, and Peccatum, a project in collaboration with his wife and fellow musician Heidi Solberg Tveitan, also known as Starofash. Since 2006, Tveitan has primarily devoted himself to solo albums and occasional guest appearances.
Beyond the characteristics typically associated with metal music, Tveitan's musical style also includes classical, industrial, and progressive elements. He is a progenitor of the symphonic black metal genre. Emperor's final album, Prometheus: The Discipline of Fire & Demise, composed by Ihsahn, epitomizes the genre.