What is a chromatic scale you say?
Well, it's this:
|------------------------------------------1-2-3-4-
|----------------------------------2-3-4-5---------
|--------------------------3-4-5-6-----------------
|------------------4-5-6-7-------------------------
|----------5-6-7-8---------------------------------
|--6-7-8-9-----------------------------------------
Now, mind you, it can be played starting on any fret.