Tran Quang Hai, Sven Gravunder, Wolfgang Saus on Voice Conference at University of Aachen 2003 Tran Quang Hai, Sven Gravunder, Wolfgang Saus on Voice Conference at University of Aachen 2003. Photo Share this:TwitterFacebookLike this:Like Loading... Related Author: tranquanghai1944 Ethnomusicologist, composer and vietnamese traditional musician View all posts by tranquanghai1944