Resident Advisor reports that Mark Bell, the pioneering rave producer and frequent Björk collaborator, has died. No cause of death has been revealed. Bell formed the acid house duo LFO with Gez Varley in the late ’80s. They were one of the first acts associated with Warp Records, and their single “LFO” went into the British top 20 in 1990. They released two albums together, and had a number of underground hit singles, before Varley left in 1996. Bell continued to record as LFO, releasing another album called Sheath in 2003. He produced most of Björk’s landmark 1997 album Homogenic, and he worked on six of her albums after that, touring with her several times as well. He also produced Depeche Mode’s 2001 album Exciter, and he released solo singles under names like Speed Jack and Counterpoint. Below, listen to some of his tracks with LFO.