Description
A thumb piano is a musical instrument belonging to the lamellophone category of idiophones. The instrument is widely used in Central Africa. The notes are produced by plucking metal reeds mounted on a sound box with the thumbs, hence the name "thumb piano." African names for the thumb piano include mbira, likembe, kalimba, tshisaji, ikembe, kasayi, sansa, and akadongo k'abaluru. Among the Shona, the thumb piano, called mbira there, has significant cultural significance. The Cuban marimbula is a type of bass kalimba. A well-known thumb piano player is Maurice White (Earth, Wind, and Fire). White named his production company Kalimba after the eponymous thumb piano. The thumb piano consists of a series of usually iron reeds (lamellae) that are made to vibrate with the fingers. These reeds are mounted on the sound box. For the metal reeds, due to a lack of suitable material, spoon handles or flattened bicycle spokes are often used. Their number varies between 8 and 24. The reeds are divided into two groups, with each hand having approximately the entire range of motion; the notes used are not set in a single series of ascending pitches, but rather divided into two more or less parallel groups. The reeds are secured by three transverse bridges, the outer two of which serve as bearing surfaces, while the middle one pushes the lamellae downward, thus securing them. Another contributing sonic element is the rings placed between the bridges around the reeds. Depending on the scale used, the sounding portion of the reeds is lengthened or shortened to achieve a different pitch. An anhemitonic pentatonic scale is usually used. This varies from performer to performer. Some instruments have several rows of lamellae. The sound box can vary considerably in shape and material: a hollowed-out rectangular block, a hollowed-out gourd, or even the shell of a tortoise. A common use is a 15- to 20-centimeter piece of semicircular bamboo, closed at the ends with semicircular pieces of wood. Wooden sound boxes are also used. A half gourd, in which the instrument is placed, is also sometimes used as a resonator. Often, several sound holes are made in the sound box, which, when covered, can alter the instrument's timbre. The songs, accompanied by the thumb piano, are either entertaining sung stories, hymns to authorities, or expressions of personal feelings. Historical and traditional themes are also sometimes sung. Melodically, the thumb piano doubles the vocal line, but it can also imitate the melody. There is always an instrumental prelude, interlude, and postlude without singing.
