Ulver (Norwegian for "wolves") are a Norwegian experimental musical collective founded in 1993, by vocalist Kristoffer Rygg. Their early works, such as debut album Bergtatt, were categorised as folklore-influenced black metal, but have since evolved a fluid and increasingly eclectic musical style, blending genres such as rock, electronica, symphonic and chamber traditions, noise and experimental music into their oeuvre. 1997 marked their international debut with the release of their third album Nattens madrigal through German label Century Media. However, following discord with the label, Kristoffer Rygg formed his own imprint Jester Records in 1998. British composer and multi-instrumentalist Daniel O'Sullivan joined the collective in 2009, and the band performed some of their first live concerts in their 15-year lifespan, including the prestigious Norwegian National Opera.