Yoruba thumb piano, made from large lightweight wooden box and wide metal blades. Used percussively as well as melodically.
Note that the tuning on these instruments relates to the tuning of the Yoruba language (a tonal language) and not to Western musical scales, although it can be retuned to suit.
View the famous Fatai Rolling Dollar(R.I.P.) playing agidigbo here:
The link below shows me playing the agidigbo in this picture: