Hi, I know nothing of theory but I do want to learn and I will.

But a question nags me from the start...

How do you know what scale to use when playing any 3 chords? What makes the root note in that scale, the root?

Sorry if this easy or been asked before. Ive been reading on here about theory and find it very fascinating to a point where its an absolute must to learn to be better at guitar.

Thanks