Stephen Maynard `` Steve '' Clark ( 23 April 1960 -- 8 January 1991 ) was an English musician best known as the co-lead guitarist and a principal songwriter for the British hard rock band , Def Leppard , until his 1991 death from an overdose brought on by a combination of multiple prescription drugs and alcohol .
Stephen Maynard `` Steve '' Clark ( 23 April 1960 -- 8 January 1991 ) was an English singer-songwriter , musician and recording artist . He was best known co-lead guitarist and a main songwriter for the hard rock band Def Leppard from 1978 until his death .