2010–present), co-lead vocals (2004–2006, 2010–present), rhythm guitar (1994–2001) Shavo Odadjian – bass (1994–2006, 2010–present), backing vocals (1995–2006, 2010–present) John Dolmayan – drums, percussion (1997–2006, 2010–present)Former members Andy Khachaturian – drums (1994—1997)Occasional contributorsArto Tunçboyacıyan — percussion, composition (on Toxicity: "Science", "ATWA" and "Arto". Steal This Album!: "Bubbles". Some live concerts in 2005, 2013)"System of a Down (Ft. Arto Tunçboyacıyan) – Arto." Genius, September 4, 2001, genius.com/System-of-a-down-arto-lyrics.Timeline''' Discography System of a Down (1998) Toxicity (2001) Steal This Album! (2002) Mezmerize (2005) Hypnotize'' (2005) Awards and nominations References External links Musical groups disestablished in 2006 Musical groups reestablished in 2010 1994 establishments in California American alternative metal musical groups Armenian rock music groups Columbia Records artists Grammy Award winners Kerrang! Awards winners Musical groups established in 1994 Musical groups from Los Angeles Musical quartets Musicians from Glendale, California Nu metal musical groups from California American progressive metal musical groups MTV Europe Music Award winners Hard rock musical groups from California