Well I finally got through Guitar Fundamentals 1 and 2, and moved on to the Rock lessons. The first chapter: "rockin' your open chords". I guess that answered my question! As I suspected though, you usually mute your 3rd interval when running a decent amount of gain. Although the A major works good with that extra 3rd.

By using 4 strings in these mostly power chords, they sound so rich and good. It takes some practice to mute unwanted strings though. My ring finger is callousing up real good. Soon I'll be able to whack all the strings without even looking, and that's when the style comes in...

Happy Holidays to you all, I hope 2021 is a productive guitar year for you all.

Matt