Piezo keyboard

I want tu build drum triggers but don't know how but my plan is to take some piezo buzzers and hook them up to a arduino UNO and that will act as a keyboard(the typing kind not piano) then use my midi program that when I hit a piezo it activates a the program any suggestions on how to do this ?

A couple tutorials that should get you started are the Knock tutorial:

This will get you started with getting the value of a piezo. Regarding the keyboard side, it's doable, but have you considered using the Arduino to generate native MIDI? It would make your solution more portable than emulating a keyboard. Tutorial: