Blues Guitar

Blues guitar provides a solid foundation to learn to play tunes and to follow a song form.  Blues is a style which developed in the 19th and 20th centuries based on the mood or feeling that accompanied the Black Experience in America. Blues provides a basis for rock music and some types of jazz. The variety and types of blues music in the world is truly astounding.
For blues to be blues, certain voicings (chords) and rhythms need to be sounded. We will explore this topic and play the blues in this lesson. We will focus on providing accompaniment.

12 bar blues progression

The above progression is a very basic from of the 12 bar blues.

A Bar

The term bar is another word for measure.  Bar and measure both mean a grouping of beats. In the example above, the beat grouping is 4. There are 4 beats per measure (bar) in this exercise. Bars are created or separated by bar lines (the vertical lines on the staff).

Slash marks

The slash marks are a visual substitute for the quarter note (in 4/4 time) [not to be confused with slash chords]. Since the slash mark is a quarter note, you can also play eighth notes (strum down-up or down-down).
You can also play triplets (rounded feel of 3 strums per beat) in place of each slash [ / = trip-o-let, or 1-2-3]. To get the blues shuffle rhythm, you play triplets, but miss the middle strum [ / = trip- -let, or 1- -3]. When you do this, this is called swinging the 8ths. You may want to play triplets, & swung 8ths all down strumming.

Roman Numerals

The above progression can be a blueprint or a template for the 12 bar blues. We can play the progression in any key (any of the 12 tones can be the I).

One, Four, & Five chords (I, IV, & V) in Popular Guitar Keys

Our example uses the Dominant 7th chords. You can play the progression using triads, but it won't sound as bluesy.

After playing the simple form of the blues, we can start making some changes. Our first change is measure 10. Going forward, we will keep any previous changes.

Changing bar 10 to the IV chord

With this change, the 10th measure is the IV chord rather than the V. This creates a bit more movement.

Changing bar 12 to the V chord

With this change, the 12th measure is the V chord rather than the I. This gets us on the path of the turnaround. A turnaround is a creative & common way to get back around to the head, or the beginning. It involves a harmonic movement which leads the player & listener back to the beginning. The turnaround typically begins in measure 11.

The Quick Four or Quick Change

With this change, we are plugged right into one of the most common 12 bar progressions, the Quick Change or Quick Four, titled for the quickness which the IV chord arrives (measure 2).
At playing gatherings, we see the Quick 4 quite often (but even with a further alteration - the complete turnaround). It is important to listen & follow the changes of blues tunes. Blues musicians do not use only one type of 12 bar, & they use 8 & 16 bar forms.
Blues guitar chord voicings