Hello, I was wondering what people mean when they talk about 'theory'. Is theory things like chords and scales or is it something else. Can some 1 please explain. I've only been playing for 6 months so im not too gd. Alos i was wondering whether it would be useful if i learnt barre chords or maybe soem one could tell me which type or group of chords are the best. I know A,C,D,E,F,G,Dm,Am,Em.
Theory is basically scales. It tells you what sounds good and why, how to form chords and chord progressions, time signatures, key signatures and all that stuff. Learn theory, and you'll have more fun songwriting.

No one group of chords are the best to use. Open/barre chords are most commonly used for acoustic work and powerchords for distorted rock music, but they're vague guidelines (Jade Puget for example uses barre chords all the time in AFI's songs). You definitely should learn barre chords whatever you play.
Quote by WlCmToTheJungle
if ur going to play some american idiot stuff heres the settings:

Master Volume : 0
i dunno about the rest