12 Bar Blues

Many of you might be wondering what is 12- bar blues. Well it is relatively very easy to understand and play the twelve bar blues. 

The most common musical form of blues is the 12-bar blues. The term "12-bar" refers to the number of measures, or musical bars, used to express the theme of a typical blues song. Nearly all blues music is played to a 4/4 time signature, which means that there are four beats in every measure or bar and each quarter note is equal to one beat.

A 12-bar blues is divided into three "four-bar segments." A standard blues progression, or sequence of notes, typically features three chords based on the first (written as I), fourth (IV), and fifth (V) notes of an eight-note scale. The I chord dominates the first four bars; the IV chord typically appears in the second four bars and the V chord is played in the third four bars. There may be few changes to this rule but it is better to understand it in this way at first. Look at the example below. There are few alterations but note the following things.

You can see the twelve bars divided into three segments. Also each segment starts with the I, IV and the V chord respectively in order.

 The lyrics of a 12-bar blues song often follow what's known as an AAB pattern. "A" refers to the first and second four-bar verse, and "B" is the third four-bar verse. In a 12-bar blues, the first and second lines are repeated, and the third line is a response to them—often with a twist.

In each 12-bar stanza, the third four-bar segment serves to resolve the previous four-bar segments. The resolution may signal the end of the song or set up another stanza. If the song continues, the transition to the next stanza is known as the turnaround

Not all blues songs follow the 12-bar format, but by understanding this basic musical framework, the listener will gain a deeper understanding and appreciation for all blues music.