Sound ball explanation

With a lot of planning and thinking I came up with the idea of the 'Sound ball'.
Using different types of strings to create different sounds and pitches. This would be highly interactive not only for your ears, but also for touch.
Sound : sound of strings as you strum
Touch : have to use hands to cause sounds to play.

The sound ball, is a ball that is split down the middle causing the ball to be in two parts. Inbetween these two parts would be 7 different types of strings that would make a interesting sound. As you open the ball the strings tighten and the tighter the strings becomes, the higher the pitch becomes, vise versa.
The ball would be made out of a sturdy but maluable metal and magnets would be placed on the rim of each ball. This ensures they stay together and the line of the ball is not interupted e.g. such as a latch, which could ruin the sleek simple look of the exterior. The strings would be attatched to a inner installation of a metal/or wood plate that has holes in it so strings could be tied and secured. With this, the strings are also free to be lose or tight, depending on what your preference is.
A problem I encountered was that you have to use two hands to operate this object and then there is nothing free to strum the strings (unless you get someone else two). I feel that if my object required two people it would take away from the whole experience of the object. Becuase I adressed this problem early on I was able to think up a solution. The most appropriate was to make a base for one part of the ball to be stabiliazed on, while the other part is free to be used and pulled up to whatever level you want. Therefore allowing this object to be used by one person, creating a a more beneficial and stimulating experience for the individual.