The thumb piano, or mbira, is a musical instrument of African origin. It generally consists of a small wooden box which can be easily held in the hands to which metal tines of various lengths have been attached. A musician generally holds the mbira with both hands and plucks the tines with his or her thumbs.There are many variants on the mbira, mostly produced by local craftsmen in the villages and townships. The instrument started being heard more outside of Africa in the 1970s (I think I still have one up in the attic somewhere).
Of course, anything can be taken to an extreme, and so I present, the five-octave thumb piano:
