Into the Pandemonium is the second studio album by Swiss extreme metal band Celtic Frost, released in 1987. The album is more varied than Celtic Frost's past LPs, with unlikely covers (Wall of Voodoo's "Mexican Radio"), emotionally charged love songs, the album's recurring industrial-influenced rhythmic songs of demons and destruction, traditional Frost-styled songs about dreams and fear, and a dark, classical piece with female vocals.
The album is vastly different from the band's previous work which cemented its late 1980s avant-garde metal term; it is also a departure from the style found on the band's previous albums, Morbid Tales and To Mega Therion that Celtic Frost had become known for. However, it does have the recurring symphonic elements found on previous albums. The album has a more classic heavy metal style within the songs with elements of industrial, classical, gothic rock and doom metal. Eduardo Rivadavia of AllMusic called it "one of the classic extreme metal albums of all time."
The track "Rex Irae" is the opening part of Celtic Frost's requiem; the third, concluding part of which, "Winter (Requiem, Chapter Three: Finale)" can be heard on 2006's Monotheist. The second part of the requiem was never released by the band. Thomas Gabriel Fischer has performed the whole piece, with the long missing second part ("Grave Eternal"), at Roadburn 2019 with Triptykon along with the Metropole Orkest. A registration of this performance has been released.
Some of the lyrics are silently borrowed from other sources. For example, significant portions of Inner Sanctum are directly quoted from Emily Brontë poems, while the lyrics to "Tristesses de la lune" are borrowed from the poem of the same name in Charles Baudelaire's Les Fleurs du mal. The lyrics to "Sorrows of the Moon" are an English translation of the same.
^ abcRivadavia, Eduardo. "Celtic Frost: Artist Biography". Allmusic. Retrieved 1 November 2014. On To Mega Therion, Warrior had begun experimenting with different musical styles (especially classical music and electronica), leading certain journalists to describe the band's direction as 'avant-garde' metal. Released in 1987, Into the Pandemonium would substantiate these claims and then some, introducing an unconventional collision of death metal brutality and symphonic overtones on its way to becoming one of the classic extreme metal albums of all time.