Hi dfaris,

"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."

.. I know exactly how you feel and it's a good place to be.

The scale you would play over any three chords would depend on what key the chords are in and if it's major or minor. Major is the 'happy' sounding key and minor is the 'darker/moody' sounding key.

If a song is in the key of 'A', there's a good possiblity that the song will start on that chord and whether that chord is major or minor would let you know if the soloing key would be A major or A minor. This is not true in every case, but a handy commonality to keep in mind.

Scales follow a pattern and the 'root' note of that scale tells you where the pattern starts. Kinda like the roots of a tree, the trunk and branches all start from there and rely on it.

Also, some of the 'patterns' or scales are related. The pattern that makes an A minor scale is exactly the same pattern (notes) that make a C Major scale - all the white keys on a piano. This relationship is called the 'relative minor'. In other words you learn 2 scales for the price of 1 !!!

As an example: sit at a piano, find the 'A' note and play each white key up to the next 'A' (8 of 'em) this will show you what the minor key sounds like. Now go to the 'C' note and play each white key up the the next 'C' (8 of 'em) this will show you what the major key sounds like..reminds me of "do a deer, a female deer"..etc.) Notice that both scales use the same notes but sound different depending on where you start ie: the root.

This should help with some basic theory understanding.

(Terminology - there are 'keys' on a piano..the black and white ones, and there is the 'key of a scale'. I referred to both, hope it wasn't too confusing)