 His field research centred on Zimbabwe, Mozambique, Malawi, Zambia, Uganda, South Africa, and Namibia, focused on the playing technique of members of the mbira and xylophone families.A highlight of Andrew's research was the identification of the lower course of tines on the karimba (i.e., Jege Tapera's mbira nyunga nyunga) as the logical ancestor of essentially all mbiras.Those eight notes can be traced through every mbira and karimba played in the Zambezi Valley, and those eight notes form the core of all kalimba music in that region, which is considered to be the birthplace of the metal-tined kalimba about 1300 years ago.