Sims was involved in several groups, the most notable of which was Citizen King, an alternative rock band famous for their 1999 hit "Better Days (And the Bottom Drops Out)", which reached #25 on the US Billboard Hot 100 chart.
Around the same time, Sims relocated to Los Angeles, where he continued his music career as a solo artist.
Sims, was a three-piece band that included Rand Twigg on bass and Andre Lange on drums.
Sims' third album, Happily Ever After (2008/Hungry Eye Records), continues on the influences of the previous release with its themes focusing on obsession, isolation, horror, and madness.
It was produced by Thomas Stern of Crime & the City Solution and features guest appearances by Jessie Evans (formerly of Subtonix, Autonervous, and The Vanishing), Toby Dammit (Swans, The Residents, and Iggy Pop), and Bryan Black (Motor).
It was also in 2010 that he collaborated with Warp Records artist Leila for her album U&I, of which he contributed his voice to her electronic compositions.