Describing a musical instrument by its physical characteristics hardly communicates its special qualities, any more than trying to communicate the taste of an orange by describing its shape and color. The mbira is more a medium than a piece of hardware.
How does one speak of the sound on an mbira, or any instrument? On the following pages we explore mbira music and mbira songs. Here are some attempts at expressing the sound of the mbira, along with some examples of mbira music.
Stroking the mbira's metal keys produces a range of sounds. Along with the vibrations of the bottle caps, the keys of the mbira tend to produce very prominent overtones resulting in various layers of rhythmic accents and inherent melodies. Mbira players often report that the mbira sounds like more than one instrument being played at once.Martin Scherzinger
The mbira’s sound has a special presence; one feels the music as much as one hears it. Its sound is penetrating and warm at the same time, immediately capturing the involvement of the listeners and drawing them into its mood. When the keys of the mbira are struck, they ring on in the gourd resonator with rich and sonorous tones "like bells," as one musician has suggested, or like flutes, as a line of classic poetry accompanying mbira music implies. There is, in fact, no satisfactory analogy for conveying its quality to one who has not heard mbira music performed.Paul Berliner — The Soul of Mbira
What's going on here?
Mbira tunes are often made up of short melodic motifs that cycle indefinitely through simple harmonies. Played with three fingers! Yet the music that we hear is anything but simple.
Paul Berliner has written about this nicely:
As (an mbira player) plays interlocked polyrhythmic parts, the complexity of the mbira’s music often gives the impression of more than one instrument being performed. Musicians explain this phenomenon in part by the fact that when they strike a sequence of keys, the keys’ pitches are sustained in the gourd resonator, overlapping and intermixing. As several patterns are repeated in a cycle their beginnings and endings become ambiguous; new phrases appear in the music as one listens to the inner parts of the piece.”
...musicians themselves observe that a single mbira can produce the effect of two or more instruments being played simultaneously. One explanation for the apparent complexity of the music lies in a phenomenon known as “inherent rhythms.” Inherent rhythms are those melodic rhythmic patterns not directly being played by the performer but arising from the total complex of the mbira music. They are the product of the psycho-acoustic fact that the ear does not perceive a series of tones as isolated pitches, but as a gestalt. For example, in mbira music in which the hands typically play large melodic leaps, the ear does not necessarily follow the precise linear melodic patterns being played; it picks out pitches of a similar level and groups them in separate independent phrases. Compositions of the Baroque period in which there is a contrapuntal dialogue between the upper and lower voices, such as the Bach unaccompanied violin and cello suites, create this effect in Western music.
As a result of all this the performer is confronted with a basic fact: the music reflected back to him by his resonator as he plays seems to be more complex than that which his fingers alone produce. It is, then, real musical feedback that the musician receives from his instrument. It may well be that this feedback is responsible for some musicians’ personification of the mbira and its role in the music-making process.Paul Berliner — The Soul of Mbira
The sound of mbira (plural)
While Shona mbira pieces can be viewed in terms of their harmonic aspects, their most characteristic feature is the complexity of the relationship among the interwoven melodic lines. And central to this interweaving is the two (or more) interlocking parts played by two (or more) mbiras in the same tuning. With each part being polyphonic in its own right. the interaction of the multiple parts creates an astonishingly multilayered sound.