There are thousands of thick, expensive theory books using sophisticated language in order to make you feel inferior to the author. And there is this website. It contains everythink you need in order to become a better musician (not only in terms of theoretical knowledge). Kudos to Mr. Adams.

Wow!!!!! It's all I got to say. It's like an extended version of the AB "bassics". A must see for everyone.

A great theory site for players of all levels, simple as that.

This website is an incredible tool for anyone from raw beginner to seasoned bass-veteran. The site offers interactive music theory lessons, ear training, and note reading training. I was stunned! You can even customize staff paper settings and print out music paper in bass clef. Really, really cool! Please check it out!