04/11/2014 Norwegian Acoustical Society, Autumn Meeting 2014, Gardermoen Flute acoustics Jens Holger Rindel Multiconsult 2014-10-24 Outline • Origins of flutes • Acoustic principles • Flutes with closed tube • Vessel (cavity) flutes • Overtone flutes • Vertical flutes • Fipple flutes (recorders) • Transverse flutes 1 04/11/2014 The Jiahu gǔdí (贾湖骨笛 ) is the oldest known musical instrument from China, dating back to around 6000 BC. Gudi literally means "bone flute". Sound generation Air stream against a sharp edge, Coltman, 1968 2 04/11/2014 Acoustical principles of flutes • Cavity flutes • Closed tube • Open tube Open and closed tubes Lowest resonances (harmonics) 3 04/11/2014 Open and closed tubes Lowest resonances (harmonics) Open – relative frequencies: 2 – 4 – 6 – 8 – 10 - 12 Closed – relative frequencies: 1 – 3 – 5 – 7 – 9 - 11 Selje-fløyten (Norwegian willow flute, combining open and closed harmonics) Chr. Skredsvig 1889 4 04/11/2014 Tone holes 1 1: Marno flute (Denmark) for demonstrating principles 5 04/11/2014 2 3 4 Flutes with closed tube 2: Pan flute, 3: Wiking pan flute (York, ca. 1000 AD), 4: Swanee flute 5 Organ pipe, closed type 6 04/11/2014 8 6 7 10 11 9 Vessel (cavity) flutes 6: Ancient (China), 7: Boatman’s whistle, 8: Nightingale whistle (Turkey) 9: Medieval (Wismar, Germany) 10: Modern clay flute (Austria) 11: Gemshorn (Germany) 12 13 Overtone flutes 12: Willow flute (Selje fløyte, Norway) 13: Txistu (Basque) 7 04/11/2014 14 Overtone flute 14: Fujara (Slovakia) 15 16 17 Vertical flutes 15: Bamboo flute (Africa) 16: Shakuhachi (Japan) 17: Tung Xiao (China) 8 04/11/2014 18 Fipple flute 18: Folk music instrument (Slovakia) - Front and back 19 Fipple flute 19: Penny whistle (Ireland) 9 04/11/2014 20 21 22 Recorders (Baroque style) 20: Alto 21: Soprano 22: Sopranino 23 24 Transverse flutes (cylindrical bore) 23: Bamboo flute (Japan) 24; Military Fife (USA) 10 04/11/2014 25 Transverse flute 25: Dizi (China) – with resonating membrane of rice paper Transverse flutes (wood, conical bore) 26: Baroque traverso 27: six keys flute 28: nine keys flute 29: Boehm ring key flute (1832) 30: Modern piccolo 26 27 28 29 30 11 04/11/2014 31 32 Modern transverse flutes (silver, cylindrical bore) 31: Normal flute 32: Alto flute (G-flute) 12.