Hi Zhenga1,

We have a number of lessons on theory you can check out here: https://www.guitartricks.com/search.php?search=theory

Also, if you're interested in rock, don't forget to check out our Rock courses here: https://www.guitartricks.com/course.php?input=rock1

Country course here: https://www.guitartricks.com/course.php?input=country1

I hope this helps!