Musical Arduino
Here’s a quick project using techniques from Spooky Projects that turns an Arduino board and a few buttons and piezos into a MIDI drum kit or scary sound trigger. Hide piezo sensors around the house during your Halloween party to trigger scary sounds when people walk around.
arduino midi drum shematic
The hardware is very simple it’s include an Arduino board with a MIDI jack, a few buttons, and two piezos attached to it. It runs off of a 9V battery.
   Musical Arduino
Go to Musical Arduino website
todbot.com