Making a Pocket Bass drum and need help!!!!

First of all excuse my ignorance, I'm just a musician :wink:
But from a beginners perspective how do i go about making a trigger with an Arduino that is sensitive to the pressure applied when hitting the trigger pad???
Coding so that the sample (in this case a bass drum) is played when i step on the pad and that the volume is dependant on how hard i hit it, how do i do that?

https://www.sparkfun.com/tutorials/330

do you want a MIDI trigger?
http://todbot.com/blog/2006/10/29/spooky-arduino-projects-4-and-musical-arduino/