A short preface: Vietnamese music is higly sincretic in which both the Indigenous forms of Vietnames music, traditions and instruments, have blended in with other influences, from neighboring countries, ethnic groups and so on. This is both reflected in traditional and contemporary sounds in Vietnam.
Citations from (web sites):
doanlachong.com (Vietnamese Musical Instruments); the site for Vancouver based local Vietnamese Musician's a husband and wife duet
Ho, Chi Khac and Hoang, Bic Ngoc
http://www.khacchi.com/instruments.html >
Vietnamese Institute of Musicology site
http://www.vnmusicology-inst.vnn.vn/english/music_instument/index.html >