The Mbira: A Musical Instrument and the Detection of Fake Medicines
A Traditional and a Scientific Instrument
The mbira is a traditional African instrument consisting of metal tines of different lengths placed on top of a wooden soundboard. The tines are plucked with the thumbs stroking down and the right forefinger stroking up to produce music. In the west, the instrument is known as a thumb piano. In the Caribbean, it's sometimes called a kalimba. The instrument is played and its music enjoyed in many countries today. Its name is pronounced um-beer-ra.
Scientists have created an instrument based on the mbira that can be used to detect the density of liquids when it's played. Tests show that the density measurement can indicate whether a liquid medicine is genuine or counterfeit. Counterfeit medicines are a problem in some parts of the world. The instrument is relatively cheap to make and would be easy to transport to areas that don't have access to expensive detection equipment.
Archaeological evidence suggests that the mbira may have existed as long ago as 500 CE. It may well be even older. It's classified as an idiophone, or an instrument that vibrates as a whole in order to make a sound. It's also classified as a plucked iodiophone, or a lamellaphone.
Structure of the Instrument
The mbira is particularly associated with the Shona people of Zimbabwe. The Shona instrument contains 22 to 28 tines, or keys, and has a range of about three octaves. Each key is wider and thinner at its tip than at its base. The keys are held in place by a horizontal metal bar placed on top of them near their base. They are held slightly above the solid, hardwood soundboard by a second metal bar underneath them, which acts as a bridge. This allows the keys to be plucked. A wooden hole is located on the right of the soundboard. The little finger of the right hand is placed in the hole, which helps to place the hand in the right position for playing.
Factors Affecting the Sound
The sound of the instrument depends on the length and size of the tines, the type of metal that was used to create them, the nature of the soundboard, and other factors. The smaller tines produce higher notes. The keys are made from new or recycled metal obtained from a variety of sources, depending on what's available. Iron, brass, or steel may be used. The pitch and tuning of the instrument varies. The bottle tops at the bottom of the instrument shown above are not decorations. They are used to produce a buzzing sound as the instrument is played. Some mbiras have either shells or metal beads on a wire instead of bottle tops.
The mbira is often placed within a large resonator, as shown in the photo below. The enclosure amplifies the sound and is known as a deze. A stick is used as a wedge to keep the instrument in position. A typical deze has a circle of attached bottle tops or shells on the edge of its outer surface. Once again, these aren't for decoration but are meant to add a buzz to the sound. Traditional dezes are made from a calabash or gourd. Modern versions are often made of synthetic materials to improve their durability.
The word "kalimba" has more than one meaning. It's sometimes used as an alternate name for a mbira, but in North America the word generally refers to a slightly different instrument with only one row of keys.
Mbira Music in Shona History and Culture
The mbira is connected to the Shona culture and is the national instrument of Zimbabwe. When it's played by a skillful musician, it can create enjoyable tunes and rhythm as well as rich and interesting harmony. The instrument is sometimes known as the "mbira dzavadzimu", which means mbira of the ancestors.
The Shona traditionally played the instrument at important ceremonies, including weddings, funerals, and events honouring specific people. The instrument was also played during a ceremony to attract the spirits of the ancestors. This event was known as the Bira. The music was intended to help people enter a trance and make communication with the spirits easier. Singing and dancing were often additional components of the event. The ritual sometimes lasted all night. It was generally performed by a group of related people who wanted to ask their ancestors for help.
Today the mbira has both spiritual and national significance for the Shona. The instrument has has been incorporated into popular music in Zimbabwe and in the west, where it appears in rock, pop, and jazz music. Often two people play a similarly tuned mbira at the same time. Each player's music complements the other's and the sounds made by the instruments interlock. An American ethnomusicologist named Paul Berliner brought the mbira and the Shona culture to international attention in the 1970s.
The mbira is the national instrument of Zimbabwe, where it holds an important place in all spiritual, political and artistic matters of the Shona people – so most people belonging to that culture will have some working knowledge of the instrument since childhood, even if they aren't musicians themselves.— David Macnamee, The Guardian
Obtaining an Instrument
Musical instruments based on the mbira are available in some music stores and can be easily found online. It may be a challenge to find an authentic version of excellent quality that also has an acceptable price, however.
Artisans are likely to provide the closest thing to a real mbira, but their instruments will probably be more expensive than store-bought ones. Some authentic instruments can be bought online. Instructions for making homemade mbiras are available on the web. When constructed correctly, the instrument is capable of producing interesting and attractive sounds, as can be heard in the videos in this article.
The mbira has inspired researchers to create a scientific instrument that may be very helpful in the fight against fake medicines. Counterfeit drugs can be a serious problem. In some countries, up to ten percent of medicinal drugs are counterfeit. Identifying these medications and making sure that sick people receive real ones are important processes.
A Scientific Instrument Based on the Mbira
Researchers at the University of California noticed that the density of the metal used to make the tines of a mbira affects the sound that's made. This inspired them to create a related instrument that is able to detect the density of a liquid. The instrument that they've produced acts as a bridge between music and science.
Like the mbira, the scientific instrument contains a long piece of metal attached to one end of a wooden soundboard and plucked at the other. The metal is in the form of single tube that is folded to make a U shape, however. The closed section of the U faces the player and is plucked, as shown in the video below. The open end is clamped to the wooden sound board.
Before it's plucked, the tube is filled with the liquid to be tested. The sound emitted by the instrument as it's played depends on the density of the liquid in the tube. The human ear may not always be able to detect the difference in sounds produced by liquids of different densities, but computer software can. It can tell whether the liquid has the density of a genuine medicine or a counterfeit or adulterated copy.
Analyzing the Liquid in the Tube
Once a sound is produced by plucking the tube in the scientific instrument, it must be analyzed to reveal information about its contents. The density of the liquid in the tube must be compared to that of the real medicine in order to discover whether the liquids contain the same ingredients in the same proportions. Unfortunately, there are two requirements for doing this which might limit the usefulness of the process in some parts of the world.
The relatively low-tech instrument requires some high-tech technology in order to be useful in the detection of fake medicines. The sound of the instrument must be recorded by a smart phone and then uploaded to web software that analyzes the sound and reports the results.
The creators say that they want their device to be useful in developing countries. Perhaps over time the system will be improved so that it can be used in areas where people don't have smart phones or Internet access. Alternatively, perhaps the required technology will become more widely available.
The research was supported financially by both the National Science Foundation and the Bill and Melinda Gates Foundation's Grand Challenges Explorations program. It would be good if further efforts by the researchers were also supported by these organizations. More research is needed in order to ensure that the instrument works with other liquid medicines besides those that were tested and to investigate the distribution of the required technology.
The World Health Organization estimates that 10 percent of all medicines in low and middle-income countries are counterfeit. Existing technologies to identify counterfeit drugs are both expensive and require expert technicians, neither of which are readily available in much of the developing world.— Holly Ober, University of California - Riverside, via the phys.org news service
An Ancient Device That Is Still Useful
I find it very interesting that such an ancient instrument as the mbira is not only being played and enjoyed today but may also indirectly help scientists solve a medical detection problem. Music, musicians, and instruments from other parts of the world have much to offer us, sometimes beyond new sounds and rhythms. The music produced by an mbira and a capable player can be very enjoyable to listen to. If the scientists who were inspired by the instrument create a device and system that significantly helps the fake medicine problem, the mbira will have made another valuable contribution to humanity.
- Information about the mbira from mbira.org (an organization devoted to Shona music)
- Mbira facts from the Grinnell College Musical Instrument Collection
- Information about the thumb piano of Africa from the Australian Museum
- An article about the thumb piano from The Guardian newspaper
- Musical sensor shows bad medicine plays false note from the phys.org news service
- Musical instruments as sensors: a PDF document from the American Chemical Society
© 2018 Linda Crampton