Mercyful Fate – Don't Break The Oath

If Melissa was the ominous incantation, Don't Break the Oath is the full-blown ritual. Mercyful Fate’s second album, released in 1984, is a masterpiece of early extreme metal—a dark, theatrical, and musically sophisticated work that helped pave the way for black metal, power metal, and prog-metal all at once.

Don’t Break the Oath builds on the twin-guitar attack of Hank Shermann and Michael Denner, blending NWOBHM influences (think Iron Maiden and Judas Priest) with baroque flourishes and sinister atmosphere. The riffs are intricate, the solos dazzling, and the arrangements more complex than most of their contemporaries. There’s a kind of neoclassical ambition here—an unholy blend of Bach and Black Sabbath.

At the centre is King Diamond, whose falsetto shrieks, ghoulish croons, and theatrical delivery remain utterly unique. His vocals aren’t for everyone, but if you surrender to his spectral style, you’ll find a frontman who turns every song into a seance.

Witchcraft, Satanic pacts, occult rites—King Diamond’s lyrics are unapologetically theatrical and blasphemous, yet rarely feel gimmicky. They're delivered with conviction, playing more like horror operettas than shock-for-shock’s-sake.

Don’t Break the Oath stands as a pillar of early extreme metal. While it never had the mainstream visibility of Metallica or Slayer, its influence runs deep: you can hear echoes of it in bands like Ghost, Opeth, and even Cradle of Filth. It also directly inspired the aesthetics and sound of the first wave of black metal. It's a triumph of metal storytelling—musically rich, dramatically performed, and cloaked in shadow. It’s an essential listen for anyone into metal’s more theatrical, melodic, and sinister side.

Best enjoyed by candlelight, with a goblet of something red and unholy.

Highlights

“A Dangerous Meeting”: The opener is a classic—tight, melodic riffing under eerie vocals sets the tone perfectly. A tale of occult gatherings gone wrong.

“The Oath”: A sprawling, operatic centerpiece that moves from solemn oaths to full-speed demonic possession. A definitive track that shows their musical and lyrical ambition.

“Gypsy”: Perhaps the most accessible song on the album, with an infectious groove and memorable chorus. Shows the band’s ability to write hooks without sacrificing their edge.

“Come to the Sabbath”: The closer and an all-timer in their catalog—a ritualistic anthem with one of their best riffs. Doom-laden, evil, glorious.

Reviews

"All of Mercyful Fate's potential was fulfilled on Don't Break the Oath, a doomy, gothic collection of post-Priest/Maiden black metal preoccupied with Satan and the occult. Hank Shermann and Michael Denner keep their progressive rock tendencies reigned in while still delivering plenty of the neo-classical feel that gives the music its atmosphere, and King Diamond uses his vocal range to great theatrical effect. Fate's sound and attitude were highly influential on later gothic/black metal bands, especially in Europe, and Don't Break the Oath consistently encapsulates their appeal." Allmusic