I'm just starting to explore music theory after picking around on a guitar for a while, and I am trying to expand my ability to improvise. I usually just play around on the neck until I find something that sounds good, and I'd like to learn the science behind why. What I'd like to learn is how to determine what scales can be played over a given chord progression. I've learned the 5 basic scales major, minor, major pent, minor pent, and blues, and I just finger within one of them at whatever spot on the neck sounds "right".
Thanks to anyone who can lead me in the right direction on learning this.