12 BAR BLUES

Ok I admit that the last section may have been a little complex but most of it is extended basically from the 12 bar blues.

I think the single most important development in jazz was the 12 Bar Blues because its theory defines the form of almost every song in jazz and blues. One reason it's so popuplar is because of its interchangable form and structure. In fact the chord progressions below should get you through, but not limited to, the following songs; St Louis Blues, Shake rattle and Roll, Hound Dog, and In the Mood by Glenn Miller.

For example the basis for the 12 blar blues is that it is written within 12 measures or bars and its content is based on 4 measures of the tonic (T), 2 measures of subdominant (S), 2 measures of tonic (T), 1 measure of dominant (D), 1 measure of subdominant (S), and 2 measures of tonic (T) and then simply repeated.

But you do not always have to follow that form as long as the extension of the chords are still used. For example if you use 7th chords the structure will look like this: (T7 T7 T7 T7) (S7 S7 T7 T7) (D7 S7 T7 T7) Just make sure the 7th chords are all dominant seventh chords.

There are alterations to the chords you can also use for example: (T S T T7) (S S7 T T7) ( D S T D7) just use triads and then add the 7th when suggested.

One thing to realize is that the blues gets old quickly and you have to use chord extensions and chord substitutions to keep the song interesting. Let's look at how Freddie the Freeloader works. It's basically a 12 bar blues. (T7 T7 T7 T7) (S7 S7 T7 T7) (D7 S7 T7 T7) But in the first ending the chord is Ab7. The Ab7 suggests a chord substitution for the last two chords of the 12 bar blues. It's actually (bVll7 bVll7). It is a chord substitution. A-flat in the key of Bb is the seventh interval so Miles Davis substituted the last two tonic chords of the 12 bar blues with (bVll7 bVll7) which sounds really hip!

Unfortunately the fake books do not give you suggestion to substituted chords. These are things that are learned through other books, lessons, and experience. One day, however these will be things that are taught in your jazz theory classes at school - it will, and already is happening.

Thanks for reading

John