Matthew Sims, commonly known by his stage name Mount Sims as well as Mt. Sims, is a Berlin-based American DJ, performance artist and producer. A native of Milwaukee, Wisconsin, Sims began his career in the local music scene. 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", which reached #25 on the US Billboard Hot 100 chart. However, Citizen King would not see any further success, and the band disbanded by 2002. Around the same time, Sims relocated to Los Angeles, where he continued his music career as a solo artist. Starting Mount Sims as an electronic music act, later releases have also shown influences from post punk, new wave, and Dark wave. Sims is almost exclusively responsible for every aspect of his music, providing vocals, instrumentation, and production. He was originally supported by three dancers, one of which was the dancer/choreographer Ryan Heffington. The last incarnation, Mt. Sims, was a three-piece band that included Rand Twigg on bass and Andre Lange on drums.