04/11/2014

1

Flute acoustics

Jens Holger Rindel

Multiconsult

2014-10-24

Norwegian Acoustical Society,

Autumn Meeting 2014, Gardermoen

Outline

• Origins of flutes

• Acoustic principles

• Flutes with closed tube

• Vessel (cavity) flutes

• Overtone flutes

• Vertical flutes

• Fipple flutes (recorders)

• Transverse flutes

04/11/2014

2

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

04/11/2014

3

Acoustical principles of flutes

• Cavity flutes

• Closed tube

• Open tube

Open and closed tubesLowest resonances (harmonics)

04/11/2014

4

Open and closed tubesLowest 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

04/11/2014

5

Tone holes

1: Marno flute (Denmark) for demonstrating principles

1

04/11/2014

6

Flutes with closed tube

2: Pan flute, 3: Wiking pan flute (York, ca. 1000 AD), 4: Swanee flute

2

3

4

5

Organ pipe, closed type

04/11/2014

7

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)

6

7

8

9

1011

Overtone flutes

12: Willow flute (Selje fløyte, Norway) 13: Txistu (Basque)

12

13

04/11/2014

8

Overtone flute

14: Fujara (Slovakia)

14

15

16

17

Vertical flutes

15: Bamboo flute (Africa) 16: Shakuhachi (Japan)

17: Tung Xiao (China)

04/11/2014

9

18

Fipple flute

18: Folk music instrument (Slovakia) - Front and back

19

Fipple flute

19: Penny whistle (Ireland)

04/11/2014

10

Recorders (Baroque style)

20: Alto 21: Soprano 22: Sopranino

20

21

22

23

24

Transverse flutes (cylindrical bore)

23: Bamboo flute (Japan) 24; Military Fife (USA)

04/11/2014

11

25

Transverse flute

25: Dizi (China) – with resonating membrane of rice paper

26

27

28

29

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

30

04/11/2014

12

Modern transverse flutes (silver, cylindrical bore)

31: Normal flute 32: Alto flute (G-flute)

31

32