Formed in Japan in 1994, the sludge metal band Corrupted were known for singing most of their slow, gutteral vocals in Spanish. Considered by most familiar with the genre to be one of the heaviest and darkest doom metal bands of all, they also they also became known for their ability to produce songs with long acoustic sections, spoken-word interludes, and other breaks in the style; their longest album El mundo frio consists of a single song substantially longer than an hour, and contains long sections of harp. Due to a band policy not to do any interviews or have professional photographers take their photo, the only known existing photographs are taken by fans at concerts.