Types: Free Reed > Aerophones.
Hornbostel-Sachs No#: 412.131
Pa Yin: 竹 bamboo.
Specimens: 1 in collection.
Region: Far East Asia.
Acquisition Source: Randy Raine-Reusch, in China.
Description: The bawu (simplified Chinese: 巴乌; traditional Chinese: 巴烏; pinyin: bāwū; also ba wu) is a Chinese wind instrument. Although shaped like a flute, it is actually a free reed instrument, with a single metal reed. It is played in a transverse (horizontal) manner. It has a pure, clarinet-like timbre and its playing technique incorporates the use of much ornamentation, particularly bending tones.
Origins: The bawu likely has its origins in the Yunnan Province of southwest China. It has become a standard instrument throughout China. The bawu is currently enjoying a popularity outside of its traditional roles. Traditionally the bawu is closely associated with Indigenous peoples who live in Yunnan China, primarily the Hmong, Yi, Hani and other minority cultures in southwestern China. It is typically used as a solo instrument, and is often featured in film scores; it is sometimes also heard in popular music recordings.
Tuning: The bawu typically has a range of an eleventh: on an instrument in “G” (according to Chinese custom) the note with three upper finger holes down) this range is from B to E. The range is often misreported as a ninth, omitting two under-blown notes. Instruments with mechanical keys are available (usually not in natural bamboo whose irregular shape would complicate construction), which expands the range upwards, or upwards and downwards a few notes.
For a diatonic scale, the lower two notes are in the fundamental mode of the reed, and the rest of the range is overblown, exciting the vibratory mode of the resonating pipe. The lowest scale degree, and the lowest overblown note are a minor third apart and fingered the same way; this unusually narrow overblowing behaviour suggests the instrument has some irregular overtones outside of the standard harmonic series.
Construction: The bawu is a free-reed aerophone with a cylindrical bore, made of a tube of bamboo closed off at one end by a natural node. Near the closed end, a small square hole is cut and a thin reed of bronze or copper is fastened, with a low plastic or bone mouthpiece around it. This reed is essentially a very thin sheet of metal with a long and narrow isosceles triangle cut into it, which is bent slightly outwards at rest.
When the instrument is blown, this thin triangle moves back and forth rapidly through the space left in the metal sheet from which it was cut, like a swinging door. This vibration sets the air column in the instrument in rapid periodic motion, creating sound. The mouth does not contact the reed. Seven or eight finger-holes are positioned 90 degrees out of line with the reed, though this is adjustable in the common two-piece instruments provided with a metal tenon.
Citations: Randy Raine-Reusch [bawu article] @ asza.com