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CCRMA – Stanford UniversityMusic 318 – Free Reed Instruments

13 February 2013

Eastern and Western free reed mouth organs: Acoustics and history

James P. Cottingham Physics Department

Coe CollegeCedar Rapids, Iowa

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Property of Thomas Rossing

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The free reed instruments --- • I. The Asian free reed mouth organs (today)

– khaen, naw– sheng, sho – bawu, hulusi

• II. Western free reed instruments (2nd session)– harmonica– reed organ and harmonium– accordion/concertina family

• III. Pitch Bending (2nd session)– harmonica– ree reeds with pipes– accordion

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I. The Asian free reed mouth organs ---

A. Overview of Eastern and Western free reed instruments with some examples

B. Some ancient Asian instruments

C. The khaen: construction and acoustics

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A. Asian Mouth Organs

Pipes

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Western Mouth Organs

No Pipes

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ACKNOWLEDGMENTS • Pat Missin (www.patmissin.com) for use of photos and sound clips.

The sound examples are played by Pat Missin.

• Terry E. Miller, Profesor Emeritus, Kent State University, for providing expert advice and opinion on the Asian free reed mouth organs, as well as video of khaen making

• Lydia Ayers, Composer and former Visiting Professor, Hong Kong University of Science & Technology for 3 animated slides of Chinese free reed mouth organs

• Financial support from: • The National Science Foundation REU Grant No. PHY-1004860

• The Coe College Acoustics Research fund

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The free reed instruments --- two main families

The Asian free reed mouth organs use flat, symmetric free reeds like the reed from a sheng (left)

The Western free reed instruments, first developed around 1800, use “offset” reeds like the one from an American reed organ (right)

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• Cross-sectional view of a free reed used in Western free reed instruments.

• The solid line represents the position of the reed at rest. • The dashed lines show approximate maximum excursions for

the blown vibrating reed. • This reed will normally only sound for a pressure difference P1

> P2. • The thickness of the reed plate (grey) varies from instrument to

instrument. • In some cases the reed tip may never pass below the reed

plate.

P1

P2

• The elastic tongue vibrates through the frame

• The reeds are symmetric: the vibrating tongue is cut from the frame

• Reeds can be chiseled form a strip of metal…

• or cut from cane or bamboo…

• The same note can sound on both pressure (exhaling) and vacuum (inhaling)

• These symmetric free reeds must be coupled to a resonator

Free reeds in Asian mouth organs

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Asian free reed instruments - History• The Asian free reed instruments are undoubtedly of

ancient origin• Most evolved as folk instruments with little or no historical

documentation• Major exceptions to this are the instruments used in the

courts of China and Japan• The sheng is mentioned in Chinese sources of the 11-12th

century BC• The Shih-Ching reports the sheng used by ordinary

people before the time of Confucius• Confucius (551-479 BC) is believed to have played the

sheng.

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The Asian mouth organs:Free reed coupled to pipe

Symmetric reeds

Often operate on both directions of airflow

Reeds normally function as a “blown open” reed

The sounding frequency is above both the natural frequency of the reed and the resonance frequency of the pipe

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Typical Asian free reed mouth organs1. Single free reed pipe with finger holes:

2. Multiple pipe instruments:

gourd pipe

khaenhulushengnaw

Complete khaen demonstrated (lai soi)

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Free-reed pipes with finger holes• Reed is placed at the closed end of a bamboo tube

• Tone quality varies with number of finger holes covered

• A variation: gourd pipe with finger holes

TM

Closed end – plugged reed

bawu

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• The bawu has a metal free reed which produces a sound similar to the clarinet.

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Free-reed pipes with finger holes• Reed is placed at the closed end of a bamboo tube• Tone quality varies with number of finger holes covered

bawu - all tone holes closed

bawu - 4 of 8 tone holes closed

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Frequency of a bawu as a function of pipe resonance frequency. Solid elliptical data points from underblowing are near the reed frequency (horizontal line).

Sound example on the free reed pipe ala (Vietnam)

Pat Missin

• One pipe similar to a bawu and one drone pipe with the reeds in a gourd wind chamber

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• A free reed mouth organ usually played by closing several pipes at a time

• The reeds are in the closed ends of the pipes in a wind chamber.

B. Some ancient free reed instruments from Southeast Asia• Some of the very simplest free reed wind

instruments:

A typical multipipe free reed mouth organ (hulusheng, naw, …)

naw (hulusheng)

Naw Pipe 1.5 Impedance

naw pipe 1.5

f1 = 433 Hz

f1 = 354 Hz

Open

mouth-resonated lamellophones (“jew’s harps”)

• common throughout Southeast Asia

• sides of the vibrating tongue cut from a single piece of wood, bamboo, or metal

• Tongue is not be plucked directly, but is excited by plucking the frame

• played by placing the reed tongue over the lips of the player and using the vocal tract as a resonator.

• Some traditional uses:– signaling– disguising the voice– imitation of natural sounds (such as frog calls)

dan moi (Vietnam)

huntoong

plucked blown

enggung(Bali)

• constructed from a single piece of bamboo

• designed as a wind instrument: • a single reed to be blown

• the player can vary the pitch by changing the shape of the vocal tract (pitch bending)

enggung

… can be used (among other things) to imitate frog calls

enggung

The free-reed horn

• Water buffalo or ox horn hollowed out and fitted with free reed:

• Wax used to seal the reed (and possibly for tuning)

• Player can blow or suck to produce one of three notes:

1. Both ends open2. Narrow end closed with hand3. Both ends closed

www.cambodianlivingarts.org

The free-reed horn

The free-reed horn

C: Construction and operation of the Southeast Asian free reed mouth organ: khaen

C. Outline• The khaen:

– Design and Construction– Acoustical properties– The khaen – an ethnographic instrument

• Video clips of khaen making - Terry Miller (1988)

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The khaen• 16 (or 6, 14, 18) free-reed bamboo pipes• Reeds of copper-silver alloy located at L/4 for

each pipe• All reeds contained in a carved hardwood

windchest• Reed section sealed in windchest by a black

insect product, kishut• Tuning slots set effective pipe length to determine

pitch• Finger holes burned in each pipe control tone

production• Player activates reed by blowing or inhaling while

covering appropriate finger holes

The khaen is the signature instrument of the Lao people ofNortheastern Thailand and Laos

Tuning slotsReed

The khaen reed

19th century Thai coinage metal has been “traditionally” used to make the reeds. [Above: Thailand 2 att (1882)]

reed

Khaen reed mounted pipe

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Sounding frequency as a function of reed length (composite for 3 khaen)

Reeds are typically made in two sizes. Pipe length is used to tune each reed-pipe to desired pitch.

Khaen Pipe Impedance CurveKhaen Pipe 4-10

Calculated Impedance

Tuning slots

reed Reed is located near L/4

Variation of sounding frequency with pipe length for a khaen pipe

The reed-pipe sounds slightly above the pipe resonance frequency

The khaen as ethnographic instrument

• Detail of martial dancers and mouth organ players from a Vietnamese bronze gong [from the Garland Encyclopedia of Music]

The khaen as a symbol of the Lao people of Northeast Thailand • Unlike many Asian traditional instruments, the khaen has not

undergone any modernization

• Despite dramatic changes in rural Thai society in the last 50 years, khaen making has not changed

• The good ones are still made by village craftsmen

• The khaen’s symbolic meaning has also changed little

• A khaen (unamplified) now often appears with an ensemble including electric guitars and drums, identifying the music as “Northeastern.”

Making a khaen reed

Strip of metal is thinned by pounding

Three free sides of reed tongue are created using a small chisel. It is traditional to use the elephant bone.

reedtongue

SEM image of portion of khaen reed. The scratches parallel to the reed tongue are from the bamboo honing blade

Video excerpts:Khaen making in a village in Roi Et province, Northeastern Thailand

Filmed in 1988 by Terry Miller

Khaen making• Carving the wind chamber • Beating kishut• Shaping kishut into strips• Assembling khaen• Finishing touches

Carving the wind chamber

Beating kishut

Shaping kishut into strips

Assembling khaen

Finishing touches

Complete khaen demonstrated (lai soi)

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Special session, Acoustical Society of America, San Diego 2011Acoustics of Mouth OrgansFollowed by - CONCERT

CONCERT Mouth Organs East and West

Khaen: Christopher Adler University of San Diego Music Department

Harmonica: Howard Levy

5:00-6:00 p.m. Monday, October 18

Garden Salon