The kalimba is an African percussion instrument, based on the more archaic mbira. The kalimba is constructed from a hollow wooden box attached to metal tines. There is a hole in the top of the box in order to allow sound reverberation.
The kalimba is played by plucking the metal tines, hence the nickname, the "thumb piano." The plucking causes a resonance within the sound box. Each tine plays a different key; the number of tones that can be created depends upon the number of tines.