Each genre of music has certain characteristics that distinguish it from other musical styles. These familiar attributes can be found in the rhythms, chords, and notes. Blues music is based on a common song form with three basic chords. This form is commonly called the twelve bar blues because it contains 12 measures. Typically contains three major chords referred to as the “one, four, and five” [I, IV, V].

Backbeat

The first step to understanding many common blues rhythms is learning to feel the ‘backbeat’ that’s common to blues music. A Backbeat is created when we intentionally accent beats “two + four” of a standard 4/4 measure. This changes the natural pulse and gives the rhythm a lively bounce. Tap your toe to a steady beat and count “one – two – three – four” repeatedly. Keep this going as you clap your hands on beats “two + four” ONLY. Now you are feeling a backbeat rhythm.

Need more help with this? Check out this lesson:
Common Blues Rhythms

The Chords

Some musicians use a numbering system to identify chords. This allows us to learn general rules about how chords blend with each other. Each number refers to the note in the scale that the chord is based on. For example, if I took the notes of the C Major scale and numbered them in order.

Stacking thirds from any note of the scale will produce a major or minor sounding chord. The chord is named after it’s first note called the root. Roman numerals are used when referring to the chord by number. The only major chords are the “one, four, five” chords [I, IV, V]. This are the main chords used in the blues.

Need more help with this? Check out this lesson:
How to Build Chords

The Form
The twelve bar blues is made of three phrases. Each phrase contains four bars. Lets explore the blues form using the chords from the key of A Major. The I, IV, V chords in that key are A, D, E respectively. To give it a bluesy sound we will make those chords into dominant seventh chords: A7, D7, E7.

First Four “The Call“

The first four measures establishes the key, the groove, and the idea of the song. It starts with the I chord [A7]. This four measure section is often referred to as the call.

Middle Four “The Response“

The middle four measures contains two measures of the IV chord [D7] before returning to the I chord for two measures. This section is often referred to as the response.

Last Four “The Turn“

The last four measures start with the V chord [E7] moving down to the IV before going back to the I. This section is called the turn short for turnaround.

12 Bar Blues

The chart shows the complete twelve bar blues progression. You can see each of the phrases we just examined. The chords in blue are common chords that are added to the twelve bar blues to spice things up a bit.

 
Here is a chart of common guitar chords to get your started exploring the blues. Each row is a different key. The white columns show the I, IV, V chords.