The links are working just fine
Yes, please do change the black BG ! I really liked what I saw in the video presentation. At first I was skeptical for the color coding of the keys, but seeing how you implement the I & V chord groups and their relation with the corresponding notes, I really believe that this method is instructive without complicating things.
I really enjoyed your site overall, and that trumpet design kicks a**
I wish you best of luck and if you get stuck anywhere don't hesitate to post (just use the eli0s to let me know) and if it is with in my abilities I'll try to help
CU around