How to make flashing police lights with sound

This is an Instructable on How to make flashing police lights with sound

Heres an example

Before i start the actual tut i just want to say this is my first tutorial, and i also want to say thank you to Dave1324 for your tutorial and also Tom Igoe for the code...

Step 1 You will need

For this project you'll need:
1 Piezo Element
1 Tri-color LED Or 1 Red LED and 1 Blue LED
Some jumper cables
1 Breadboard
1 Arduino or suitably similar thing (I use the arduino Uno) 

Optianal:
Resisters (I dont know the strength needed cause i dont use the for this project)