You Must Be Certain of the Devil

You Must Be Certain of the Devil is the fifth album by American avant-garde performer Diamanda Galás, released on May 23, 1988 by record label Mute.

Content
You Must Be Certain of the Devil is the final instalment in her "Masque of the Red Death" trilogy about the AIDS epidemic. The selections from this instalment are rooted in American gospel music.

Personnel

 * Diamanda Galás – vocals, organ, piano, synthesizer, keyboards, production
 * John Dent – mastering
 * F. M. Einheit – drums (B2), chains (A2)
 * Naut Humon – samples
 * Gareth Jones – production
 * Kurt Schmidt – guitar (A2 & 4)
 * Pete Schmidt – engineering
 * Charlie Terstappen – drums
 * Peter Zimmermann – percussion