This is the most recent Njari that I have built. Below is a diagram of the note layout that I have developed and become accustomed to playing.
In this 39 reed instrument that spans 3 octaves and a third I have managed to keep the traditional pair of mid and high 4’s for each thumb as well as include a mid 3 on the right lower rank which is bent up (as in Matepe) to gain the access of the left thumb too if it happens to be hanging around in that area at the required moment. Before I build an Njari for somebody I ask for the measurement of the distance between the tip of their left thumb and left middle finger. This measurement determines the width of the soundboard they will get. The owner of the Njari above has smaller hands and therefore I have beaten the reeds less in order to create a narrower soundboard. (The result is longer reeds.) I also gave the wood a waist to help in that regard and the rest of the reach needed will be attained in the natural gradual stretching of their palm muscles through playing.
Typically in Njari the 4 outer left reeds are plucked from below with the forefinger while the thumb can be playing the same notes an octave higher or lower. The mid range 1,2,3 (on left) can also be plucked from below with the forefinger while the thumb can choose between the lower octave 1,2,3 or a variety of octaves of 4,5,6. I use spring steel and brass for the reeds and in the lower octave each reed has three tuned notes:- the fundament, the 1st overtone 2 octaves and a third higher and the 2nd overtone an octave and a third above the 1st overtone. Therefore the deepest note 1 is comprised of a chord 1-3-5, the 2nd note a chord 2-4-6 and so on up.
For me the greatest challenges in building any mbira are in settling the bridge into the wood evenly for optimum sound transmission into the soundboard and in tying the bar onto the headstock perfectly so that the reeds are held with the correct pressure. Not too tight that they struggle to get in and not too loose that they need to be constantly bent to attain adequate tension. I choose to tie the bar onto the board traditionally rather than use nuts and bolts.