‘Themes from William Blake's The Marriage of Heaven and Hell’ is the fourth studio album by Norwegian experimentalists Ulver.   Having been known for their more folklore-tinged black metal compositions on early studio releases, in late 1997, mainman Kristoffer Rygg invited keyboardist, sound conceptualist, and composer Tore Ylwizaker into the collective, and together they devised a plan for The Blake album; an altogether far more adventurous endeavour than prior releases.   What resulted was a seamless integration of electronic and industrial music, with elements of progressive metal and avant-garde rock, all fused with ambient passages while following Blake's plates as track indexes. Upon release, the album received widespread acclaim from critics within the rock, metal and alternative music press, being awarded Album of the Month in several high-profile magazines such as Terrorizer, Metal Hammer, and Rock Hard. The album notably includes guest vocal appearances from Darkthrone’s Fenriz, as well as Ihsahn and Samoth, most known for their work in Emperor.