KRS-One has been quoted as saying that he was close to joining Ultramagnetic MCs early on. Paul C. was also a major contributor to "Critical Beatdown", producing "Give The Drummer Some," and engineering most of the album. Paul C. also produced the Hip-House mix of "Traveling At The Speed Of Thought", which was used as the group's first music video, and was their sole release in 1989. The single's b-side, "A Chorus Line", became one of Ultramagnetic's most popular songs and introduced new group affiliate Tim Dog. A variation of the "A Chorus Line" instrumental was used as the basis of Tim Dog's debut single, the Ced Gee-produced "Fuck Compton", which became a modest hit and is credited with helping to spark the East coast/West coast feud of the mid 1990s. The group went on a hiatus for several years, breaking up temporarily in 1990. They returned on Mercury Records in 1992, with the album "Funk Your Head Up". The album received a muted response, in part because many tracks had been given a commercial sheen, having been remixed by outside producers at the label's insistence. Alternate mixes of this album's songs along with unreleased tracks from the sessions have appeared on later compilations. The song "Poppa Large", remixed by Da Beatminerz, became a hit and remains a staple of Kool Keith's live show. The song's video featured Keith in a straitjacket, his bald head encased in a birdcage. In 1993, the group released the album "The Four Horsemen", which featured guest production and vocals by Godfather Don, who produced solo Kool Keith sessions in 1992. Some of those tracks appear on "The Four Horsemen", and also on The Cenobites LP. The former was the last official album the Ultramagnetic MC's released until their 2007 reunion. There were many semi-legitimate and compilation albums to follow, the most official of which was Next Plateau's "The B-Sides Companion", which featured a new song, some unreleased 1989 songs recorded for a second Next Plateau LP and most of the group's classic singles, albeit in newly remixed form. Ced Gee and Moe Love both provided demos and unreleased songs spanning the group's entire career to Tuff City for a series of four albums which were released without Kool Keith's consent. A live album, "Brooklyn To Brixton", was announced but abandoned.