Monday, March 30, 2009

Blackwood used in Musical Instruments

If you have ever heard the mellow tones of a jazz or classical clarinet solo, you have been listening to the natural sound of an instrument made of mpingo. In the last century, cocuswood from the Caribbean region was the wood of choice for woodwinds, but the species was driven into economic extinction by that demand. African blackwood is now the wood used exclusively for fine quality woodwind instruments. Their manufacture demands a perfect piece of wood free of all defects to allow the intricate machining necessary to create such a complex instrument. To quote flutemaker Casey Burns, "African blackwood, which makes an excellent flute, is now the standard by which all other flute tonewoods are judged."

Since blackwood is a tree that grows twisted and full of flaws, extracting high quality timber is extremely difficult.mpingomusicblanks.jpg (18276 bytes)Graders at the mill reject up to 90% of the wood to the scrap pile. Additionally, instrument makers are finding that they lose up to 20% of their workpieces during the machining process at the factory. It is thought that this may be due to the exposure of mpingo to fires in excess of what would occur naturally during its growth. This may create hairline cracks and invisible defects in the wood that cause it to explode apart on the lathe during manufacture. Such large amounts of wastage put an added demand on the remaining stands of timber.

African blackwood's exceptional stability under extremes of humidity and temperature is a necessary characteristic for instruments played by blowing air into them. Its density and fine grain structure allow it to be machined much as if it were metal. Its tight grain and oily nature allows it to be polished to a beautiful sheen. Not only does blackwood have no peers for this purpose, no suitable natural replacement is known. Composite materials made of blackwood dust and resins, as well as various plastic compounds have been used for the manufacture of woodwind instruments, but their acceptance among professional players is poor.

The clarinet is perhaps the best known of the woodwind instruments and serves as an illustration of the indispensable place blackwood holds in the world of music. The clarinet consists of a cylindrical tube with a bell-shaped opening at one end and a mouthpiece at the other. The mouthpiece has a flat cane reed attached which vibrates when blown upon. This vibration produces a full, rich tone. The tube contains open holes and holes covered by keys. The fingers open and close the holes and operate the keys to produce notes within a range of over three octaves. The complex machining required to produce this configuration produces an excellent result when the wood is mpingo.

Blackwood clarinets are known for their warm and beguiling musical tone. Most professional musicians feel there is no substitute for an instrument made of blackwood. Acker Bilk, well-known clarinetist for such pieces as "Stranger on the Shore", had this to say about mpingo clarinets in the PBS video, "The Tree of Music": "It's got that warmth about it, that live sort of feel about it–wood–you can't beat it!"

Mpingo also figures prominently in the making of bagpipes. bagpipes.jpg (10592 bytes)A bagpipe is a wind instrument which produces sound through reeds. Except in a few special cases it is made of at least two sounding pipes tied into an airtight bag with a further pipe to allow it to be filled with air. Pressure is applied to the bag using the arm, and this causes the reeds to vibrate and sound. Mpingo is an excellent material for the sounding pipes of this instrument.

Most of the mpingo harvested in eastern Africa goes to the music trade, its primary economic use. Some rough estimates, such as cited in the "Tree of Music" video, say that there are about 3 million mpingos in Tanzania. Of these, only about 600,000 are suitable for the music trade. Since there are between 20,000-30,000 trees harvested per year, one can calculate that there only remains a 20-30 year supply of harvestable mpingo. Of course, other trees growing may mature into suitable candidates for harvesting, but the natural regeneration of mpingo has been negatively impacted by the increasing pressure of human activity. Set-fires, for agricultural purposes, have a considerable impact on the mpingo population, since its natural resistance to fire is not strong enough to resist the human-set fires which are more intense and occur more often than natural fires.

Fauna and Flora International, a conservation organization in England, has been instrumental in gathering information about the status of mpingo in recent years. It has created a project called SoundWood to address conservation issues concerning the woods used in musical instruments. SoundWood conducted a conference in Maputo, Mozambique in the winter of 1995 to discuss the mpingo tree--its status and implications for its future conservation.

 

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