open flutes with internal duct. 421.222.11 Without fingerholes - Open flue stops of the organ. 421.222.12 With fingerholes Double flageolet. 421.222.2 Sets of partly stopped flutes with internal duct. 421.222.3 Sets of stopped flutes with internal duct. Paixiao References http://www.music.vt.edu/musicdictionary/texta/Aerophone.html http://www.wesleyan.edu/vim/svh.html Category:Woodwind instruments Edge-blown aerophones