One of Reznor's earliest collaborations was a Ministry side project in 1990 under the name of 1000 Homo DJs. Reznor sang vocals on a cover of Black Sabbath's "Supernaut". Due to legal issues with his label, Reznor's vocals had to be distorted to make his voice unrecognizable. The band also recorded additional versions with Al Jourgensen doing vocals. While there is still debate as to which version is Reznor and which is Jourgensen, it has been definitively stated that Reznor's vocals were used in the TVT Records' "Black Box" box set. He also performed with another of Jourgensen's side projects, Revolting Cocks, in 1990. He said: "I saw a whole side of humanity that I didn't know existed. It was decadence on a new level, but with a sense of humor."