Original rounded body Greek bouzouki had 6 string instrument with 3 courses, trichordo. In 1950s, 2 more strings developed for tetrachordo. PAIRS give more bass sound. In mid 1960s, Johnny Moynihan - folk singer in Dublin, Ireland- introduced the bouzouki into Irish music. Soon body was widened w flat back. RESEARCH by DdO:) - http://www.pinterest.com/DianaDeeOsborne/instruments-for-joy/ - INSTRUMENTS FOR JOY. Interesting pin via Manfred Hennessy.