Jazz Theory 7 BASIC BLUES and the Blues scale Origin of the Blues Form Basic Blues in C Basic Blues harmony Velocity Blues The Blues scale Bb- and Eb- instruments Quiz - Quiz Answers Ear test 15 - Answers Lesson Material - General files Jazz Theory lessons online

JT 7.1 - Origin of the Blues

The Blues is the most important musical form in Jazz and Jazz-related music. The Blues started in the 19th century as a form of folk music developed by the black slaves in the United States. Originally blues were very loosely structured songs performed by individual singers, guitarists and banjo players. The lyrics were usually sad and dealt with every day issues of slave life. When the blues spread from the country side to urban centres their content included more happy aspects. By 1920 three distinct blues formats had developed : the 8 bar blues, the 12 bar blues and the 16 bar blues. From these three the 12 bar blues quickly became the most popular form. It is still the most common blues form used by contemporary musicians.

JT 7.2 - Form

The 12 bar blues consists of three phrases. Each phrase is four bars long.

In its original vocal form :

For example :

Repetition of melodic or rhythmic phrases or motifs is also very common in many instrumental blues , although it is not essential. Repeated motifs are commonly either 2 bars long or 4 bars long.

The blues can be played in any key. The most common keys are C, F, Bb, and G

JT 7.3 - Basic Blues in C

The most basic chord progression of the 12 bar blues in C is :

• The I chord (C) covers the first two bars (1 and 2) of the 1st phrase.
  
  
• The IV chord (F) covers the first two bars (5 and 6) of the 2nd phrase.
  
  
• The V chord (G) covers the first two bars (9 and 10) of the 3rd phrase.

JT 7.4 - Basic Blues Harmony

The basic harmony of the 12 bar blues contains three different chords :

Audio 2


(Arabic numerals (1, 2, 3, etc.) represent individual scale tones or chord tones. Roman numerals (I, IV, V, etc.) represent chords.)

The Chord progression in the 2nd phrase of the blues

IV chord ---> I chord
(F ---> C in the key of C)

is know in Classical terminology as a Plagal Cadence.

Audio 3

This chord sequence underlies many endings of church hymns and is therefore also known as the Amen Cadence.

The chord progression in the 3rd phrase of the blues

V chord ---> I chord
(G ---> C in the key of C)

is know in Classical terminology as a Perfect Cadence.

Audio 4

The V chord is in many Perfect Cadences not a triad but a 4-note seventh chord (G7 above).Seventh chords are dealt with in Lesson 8.

This chord sequence underlies many endings of classical music as well as Jazz standards and Popular music. It is also known as a full close.

A basic blues progression contains therefore both a Plagal and a Perfect Cadence.

JT 7.5 - Velocity Blues

Velocity Blues is a tribute to Carl Czerny writer of his famous Opus 299 School of Velocity, still an essential work of exercises for professional keyboard players (Oscar Peterson amongst them).
The melody consists entirely of chord tones.

Audio 5

Audio 6

(Compare this with Audio 1 , where all three chords are played in root position.
Can you hear that the voicings jump too much up and down ?)

Always play a closed position chords in the recommended range.

For Velocity Blues play a steady short chord on each beat in the bar.

See the Blues Book for 30 more fun Blues songs to play. Or join the Jazclass Blues Email Course with 10 lessons covering all aspects of the Blues, including many songs.

JT7.6 - The Blues scale

The Blues scale is perhaps the best known scale for improvisation over the blues.
It is very popular as it requires only the one scale for the entire blues progression :

• for the blues in C - use the C blues scale

• for the blues in F - use the F blues scale

• For the blues in A - use the A blues scale, and so on

The Blues scale is a 6-note scale.
It consists of the scale tonic note, its associated perfect 4th and perfect 5th, and the three so called blue notes :

• the minor 3rd (b3)
• the tritone (b5), and
• the minor 7th (b7)

Audio 7

The three blue notes clash with some of the chord tones.
For example in the blues in C

• the Eb clashes with the E of the C chord (C E G).
• the Bb clashes with the B of the G chord (G B D).
• the tritone Gb provides a transition from F to G. This simulates the bending of note pitches, so typical of the early blues singers.

The overall effect of clashing and bent notes creates the unique flavour so typical for the blues.

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JT 7.7 - Bb- and Eb- instruments

Bb instrument players (trumpet, clarinet, soprano- and tenor-sax) : To match the 'concert key ' of keyboards, flutes etc. play in the key 2 semitones higher. For example for the Blues in C : play in the key of D For the Blues in F : play in the key of G Eb instrument players (alto- and baritone-sax) : To match the 'concert key' of keyboards, flutes etc. always play in the key 3 semitones lower. For example for the Blues in C : play in the key of A For the Blues in F : play in the key of D

JT 7.8 - Quiz

A.
1. How many bars are there in the basic blues form ?

2. How many phrases are there in the basic blues form, and how many bars is each phrase ?

3. How many different chords make up the chord progression of the basic blues, and which are they ?

B.
1. Which chords are there in the chord progression for the basic blues in the key of F ?

2. Which chords are there in the chord progression for the basic blues in the key of G ?

3. Which chords are there in the chord progression for the basic blues in the key of Bb ?

C.
A music student is learning the guitar.
So far he has learnt to play the following chords : C - E - D - G - A - F - Bb
In how many keys can he play the basic blues ?

D.
What are the Perfect Cadences in the major keys of E, of F, of G and of Bb ?

E.
What are the Plagal Cadences in the major keys of E, of F, of G and of Bb ?

F.
Mark the Blues scale in all keys on the Keyboard Diagrams.
Highlight the three 'blue notes' in a different colour as shown here for the C Blues scale.

What music element can be formed by combining the three blue notes in any key ?

G.
Mark the Blues scale in all keys on the Scale Letters Diagrams.

Use the note numbers : 1 - b3 - 4 - b5 - 5 - b7 - 1.

Here an example for the E Blues scale :

JT 7.9 - Ear test 15

Identify the following Perfect and Plagal Cadences. Each Cadence is played twice.

JT 7.10 - Lesson Material