Heh...here's an edge I might have in explaining some parts of blues....I'm from Mississippi, where it all started. In fact, Greenville is about 45 minutes away from my house. When someone writes a blues song, there pretty much telling a story in musical context. Listen to the lyrics of most blues songwriters and you'll see that there's almost always an underlying story. Sometimes they're fictional, sometimes they're based on part of the writer's life. I've got a blues song called "There Stands a Girl" that's written from the perspective of an older man watching a young girl throw her life away due to poverty and being an orphan. She turns to prostitution to make money and the old man tries to show her a better way to go about things, but she won't listen. Anyway....the theory behind blues music is so simple...yet so complex. It's because of the freedom the style offers as far as composing goes, thanks to using passing tones. You don't necessarily have to stick to everything that's ordered in the world of music theory to write a blues song or solo. If it's done tastefully, a blues player can throw in notes that may be completely out of key, but they fit because of the "soul" in the music and because they're used as passing tones from note to note. It's hard to explain, but easy to understand. It's also very easy to play blues solos, as they're based on pentatonics...just make sure you're playing with feeling if you ever play in front of a real bluesman or he'll frown upon your music . Watch the movie Crossroads if you've never seen it. It features Steve Vai and it explains blues in a fun way.