The historical roots of most jazz, rock and plenty of American Folk and classical music lie in the blues. No one lesson could do more than scratch the surface of an area so vast as the Blues, but this will serve as a brief intro for guitarists. It may help to first check out the Theory Mini-Lesson, but here is a basic 12 Bar Blues structure:
This pattern repeats and is called a "progression." The easiest way to get started is in the key of A.
·The I-chord, A, will be just two notes the open 5th string and the 4th string at the 2nd fret, held down by the 1st finger of the left hand. Pluck or strum both strings in a swing rhythm of long-short-long-short, etc. One "long-short" pair equals one beat; four beats, or four pairs, is one measure.
·The IV-chord is made by shifting the I-chord over one string to the open 4th string and the 3rd string held at the 2nd fret.
·The V-chord is made by shifting the I-chord over the other direction to the open 6th string and the 5th string held at the 2nd fret.
·Follow this progression repeatedly. Teach it to a buddy, and you're ready for the next part - what scale to play while your buddy plays the progression. Here are the notes: 6th string, 5th fret and 8th fret; 5th string, 5th, 6th and 7th frets; 4th string, 5th and 7th frets, 3rd string, 5th, 7th and 8th frets; 2nd string, 5th and 8th frets; and 1st string, 5th and 8th frets. This is called a "box" because you can easily reach all the right scale notes in two octaves in this four-fret space. Again, use a swing rhythm as you change from note to note.
·Figure out where else on the neck these same notes and their octaves are to find ways of playing elsewhere on the neck while staying in the same key of A.