American heavy metal and punk rock guitarist. He is best known for being the rhythm guitarist with Suicidal Tendencies from 1987-1995 then returned to the band in 1997. He originally played in the thrash metal band No Mercy of which Muir was also the vocalist. During Suicidal Tendencies' hiatus he was a member of the thrash band Creeper. Currently playing guitar in Great Gods Of Greed.