In 1990, Anthrax released the more serious Persistence of Time to even greater success than State of Euphoria. The album was considerably darker but much more technical and progressive than Anthrax's previous work. This made it a hit with metalheads who were afraid to embrace the band because of their "silly" side. The biggest single off the album was a cover of Joe Jackson's "Got the Time". Jackson himself even claimed that he enjoyed Anthrax's cover version of his song. The band's own original song "In My World" as well as "Belly of the Beast" were extremely and moderately successful, respectively. Anthrax was always a band prone to experimentation; in 1987, they appeared on the title track of rap group U.T.F.O.'s album Lethal. In 1991, they collaborated with pioneering rap artists Public Enemy on a joint version of PE's "Bring the Noise", although Anthrax already did a fusion of rap and heavy metal in the form of "I'm the Man" in 1987, a comedic song originally slated to be played with the Beastie Boys (although they did not actually get to play this song with Anthrax until a 1991 remake). "Bring the Noise" was a hit, and the band had a successful joint tour with Public Enemy.