I know someone asked in here about the mixolydian mode. It will link into what i am talking about, which is blues. The Mixolydian mode is derived from the major scale, by starting on it's 5th note. It's used to improvise over 7ths.
Here is something I found around the internet: Listen to this lick....(For me clicking on the link and it will play through Quick Time, you might have to change it to what suits your computer)
http://www.gibson.com/products/gibson/s ... twood1.mp3
Now that Blues lick is near enough this when tabbed out (although a couple of notes are wrong I think but you get the idea) Take a look:
Now as you can see that lick is based on A7 that means the notes are- A B C# D E F# G A - That contains the notes of the chord A7. Which is the chord the lick is based on and around. This is derived from the scale by starting on it's 5th note.
To know and understand the Blues you need to know about the pentatonic Scale. Pentatonic means just the 5 notes. Pentatonic minors are heavily involved within Blues and to know about Blues it worth studying these in depth. It is of course the Blue note of the scale that give it the blues lilt, that extra little kick that makes us say that "Thats the Blues" But the difference being that you don't have to worry about changing scale to change chords. In Blues A you can carry rigt on with the A Pentatonic when you get round to the D7 and E7 chords. You cannot do this with Mixolydians, the A Mixolydian works only with the A7 chord. You could of course change D to E and that would be fine but you would be moving away from Blues and aiming more towards Jazz..and Jazz is a lesson for another day!!
Great Blues Players mix there scales and play lots of apreggios smoothly and always in a way to flow nicely in and out and back to a certain lick. I think the Blues is not something that requires a great deal of theory but you need to know all about the Blues Scale and how those Blue notes relate to a scale that could be any other. The Pentatonic is really the starting point.
To learn more click on this link and print off those scale drawings and learn them, it will help as a starting point, check it out:
Again I hope this post will come in handy to someone and you find it intresting, please feel free to ask anything, correct me or add to what I have put.