New to Arduino (Midi string instrument)

Hi! I'm completely new to the world of arduino and a little help/guidance would be muchly appreciated!

I'd like to make a string instrument that triggers a midi note when a string is plucked. This instrument would not be fretted and would only trigger 1 note per string (6 strings) so there is no need for pitch detection. I have some piezo guitar saddles lying around that I believe would work perfectly for the application, they look like this...

The string rests in the little saddle and the piezo sensor would pick up every time the string has been plucked. I'm not sure if this is a problem but there seems to be no ground coming from the piezo, just an active wire, is this normal? Can it still work? Is there an easier way to set something up to detect when a string has been plucked?

So my plan is to have the 6 individual piezos running into an arduino board, the piezos would pickup when the string has been played and the arduino would translate that into a midi note and which will trigger a sound in logic pro. Does this sound reasonable?

Or maybe I've picked a project a bit too difficult for someone who's new to arduino? lol

Thanks guys and gals.

I can't see how it would work without a ground, so I assume the body is the ground. Try hooking it (the wire and the body) up to a test circuit and see if something happens when you pluck it.