Question: Are both Ontronik Khachaturian and Siouxsie Sioux singers and producers?
Sentence (from "Ontronik Khachaturian"): He is known for being the original co-founder/drummer (1993–1997) of the Grammy Award-winning metal band System of a Down and founder/lead vocalist (1999–2002) of the alt-progressive rock band The Apex Theory.
Relevant evidence: Yes