In 1995 I was given a mbira by Dr. Dumisani Maraire, who was my lecturer at the Zimbabwe College of Music. It was a homework for me, to reseach on that instrument, which reached his hands as a"Shangani Mbira". Knowing that I was a Shangani boy, Mariaire asked me whether I knew that type of mbira. But, unfortunately, even after my extensive fieldwork in Mozambique, I had not come across such a mbira -Mbira culture was almost extinct in Mozambique! However, the homework was set, whose results only came later.
Ten years later, when I started to reseach on mbira building, in 2005, this mbira fell in the pool of my raw materials for experimental endeavour. In fact, it was for me raw! I, then, remoned its original keys, whose musicology I c had not figured out; cut some circular shapes on the board, to give it my character, and fitted new keys, made from stripes cut out of a steel sheet with a hand grinder, in a mbira dzavadzimu format. few keys were close to the desired pitches, but most were descrepant.
Conducting analogical/comparative experiments with xylophone key tuning procedure, of redistributing mass -shifting/adding/removing- through the key's length to alter its acoustical behavious, I figured how to raise and drop the frequency of the key without changing its length or width -that was the tuning formula that became to be used by most mbira makers in Maputo.