Zimbabwean marimbas have not been around for as long as you might think. The modern-day Zimbabwe-marimba was invented (or perhaps, reinvented) in the 1960’s, at Kwanongoma College of African Music in the city of Bulawayo. Prior to that, marimbas as traditional instruments had been extinct in Zimbabwe for several hundred years, although they have existed in the surrounding countries. In Mozambique in particular, the craftsmanship of marimba construction as well as the artistry of playing is extraordinary, and has been that way for at least four or five hundred years.
Here is the story of how marimba bands began in Zimbabwe, from Chaia Marimba Music Book 2.
Check out this great video