Question: Which Amercain based professional also sang in Armenian, Turkish, and Assyrian, Pete Mangurian or John Bilezikjian? 
Sentence (from "John Bilezikjian"): He was also a traditional and contemporary singer singing in Armenian, but also in Turkish, Assyrian/Syriac, English and known for his contributions to world music as a solo act and in collaborations with renowned artists.
Relevant evidence: No