A while ago I started feeling weird about not knowing any theory. Sure I could use the Pentatonic, Major and natural minor to outline chords and the likes but without great techniques to hide it all by playing fast, it didn't really get me far. So I sat down with two Total Guitar magazines on the 'Satriani explaines modes' pages and tried to figure it out. Now the magazine put it in a VERY confusing way but I got it. Basically, a mode is when you start the Major scale from a different note:
C D E F G A B C
1 1 1/2 1 1 1 1/2
Still using the same root note, you place the intervals starting at the 6 other notes:
1 1/2 1 1 1 1/2 1
1/2 1 1 1 1/2 1 1
1 1 1 1/2 1 1 1/2
1 1 1/2 1 1 1/2 1
1 1/2 1 1 1/2 1 1
1/2 1 1 1/2 1 1 1
1 1 1/2 1 1 1 1 1/2 <- major scale back again!
Each mode is like a different scale in itself, but they're fairly easy to figure out once you know the intervals. Minor modes all include the Pentatonic intervals ( 1 b3 4 5 b7) and major modes have a major third.
The Mixolydian is a rocker's favorite because its b7 outlines a 7th/DOM7 chord very well. Slash is known for using it. The Dorian I believe is a favorite of ZZ Top's Billy Gibbons, while Yngwie Malmsteem favors the Phrygian mode (sometimes refered to as having Spanish hints when played over minor chords, another thing to try and include in your playing!. The Aeolian is mostly known as the Natural Minor scale and is the second most favorite scale in rock. These three examples are minor scales and therefore sometimes the extra notes compared to the Pentatonic Minor can be used with good effects on certain chords, or to create different intervals.
What these showed me, after trying the different flavors, is that it's not very important knowing SHAPES if you know the notes on the fretboard. Shapes limit you. I used to be stuck in the standard pentatonic shape, but you can do a lot more with all the notes that are on the fretboard that fall into that scale.
I had two files ready to upload on here, one showing all the modes' shapes (one position only though) and some chord intervals as well as how they were constructed, and another with all the Pentatonic notes on the fretboard as well as some suggested uses. But I can't upload them anyway... I'll have the Net back Sunday since I'm going back to the land of Tulips so I'll try to post it. Tell me what you think so far guys, I'm thinking of writing a quick guide to beginner's guitar theory!