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The blues: musical genre, blues scale, blues progression

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What is the blues? The answer to this question is not as simple as it may seem, in fact the term 'blues' refers to many different things, all of which have to do with music, but the point of view can be very different. In this lesson we will discover different uses of the word 'blues', and why it is important for a musician to know them all.

The term 'blues' basically means three things. To begin with, the blues is music that originated in America in the mid-19th century in the African-American community. In this sense, the blues is a musical genre that embraces an entire repertoire of songs and pieces of music, as well as the performers who have made its history.

The term 'blues' also indicates a precise musical scale, derived from the pentatonic scale but with certain differences. The blues scale is used in the blues repertoire, but not only in this. For example, it is used in rock and jazz, which are musical genres quite distinct from the blues.

Finally, the 'blues changes' is a very precise musical form, consisting of 12 measures. This form originated in the blues repertoire, but was used even more by jazz musicians, who adapted it to their own purposes. The blues progression has since been used in other musical genres, such as rock'n'roll, pop, rock, songwriting and others.

Let us now analyse each of these three meanings of the word blues in order to better understand its many nuances.

The blues, music genre

The blues is a musical genre that originated in the south of the United States in the second half of the 19th century and in the African-American community, i.e. among the descendants of African slaves deported to America in previous centuries.

Like other musical genres that developed in America at that time, e.g. the spiritual and the gospel, the blues also brought together elements that were specifically African and others of European origin. In fact, not only African slaves arrived in America, but also millions of emigrants from all over Europe.

With regard to the blues, African music clearly predominates over musical elements of European origin. However, the specific weight of the different musical cultures that have met and melted in America is being studied and debated by researchers and scholars, not only with regard to the blues but also to other specifically American musical genres.

When talking about the blues, in the sense of a repertoire of songs or musical genre, it may be useful to distinguish between two main currents: the rural blues, born in the countryside, and the urban blues more typical of big cities.

Rural blues

The blues, intended therefore as a musical genre, was much neglected until almost the middle of the 20th century, when two scholars, a father and son named John and Alan Lomax, became passionate about this repertoire and carried out investigations in the southern United States.

John and Alan Lomax made an effort to record the main performers of this musical genre, doing extremely valuable work and laying the foundations for the discovery of the blues by musicians all over the world.

Until then, the blues was a popular music, transmitted orally by self-taught musicians without any academic training. Bluesmen were singers who accompanied themselves with a guitar, playing mostly solo and often improvising much of their performance.

In the blues, improvisation did not only concern the instrumental part, but also the lyrics, which were adapted to the context of the performance. From this point of view, bluesmen were storytellers, often itinerant and with an adventurous life.

It is not surprising, therefore, that in order to meet and record some blues performers, John and Alan Lomax had to join them even inside American prisons, where some were imprisoned for fights, stabbings and adventures related in some way to their wandering.

Some important performers of this repertoire, which we also called 'rural blues', are Leadbelly, Muddy Waters, Robert Johnson and John Lee Hooker.

Robert Johnson
Robert Johnson

The wandering bluesmen who sang and accompanied themselves on guitar did not have a musical career in the modern sense of the term, they did not attend theatres and were not considered concert performers.

It is believed that their way of singing and playing the blues is closer to that of their origins, although the most recent records date from the 1930s or later. Starting in the 1920s, numerous recordings of more sophisticated blues pieces were also made in cities. We classify this repertoire as 'urban blues'.

Urban blues

We have said that rural blues was sung by self-taught musicians, predominantly male, who roamed the countryside and accompanied themselves with a guitar. At the same time, from 1920 onwards, a flourishing record market was created that recorded blues singers, in this case almost always female, and backed them up with real bands.

Some protagonists of this musical genre were the singers Mamie Smith, Ma Rainey, Bessie Smith. In this case, they were professional singers, often Vaudeville performers, in other words, travelling shows entertainers.

These singers were part of real companies of artists, and not infrequently they were at the head of them. They were often welcomed in the cities almost like modern stars, and some far-sighted promoters realised that their records could have a very good market.

In their recordings, these singers employed professional musicians. Often there was a pianist leading the band, the arrangements were carefully written or at least decided in advance, with instrumental solos, introductions and well-structured endings.

The recordings we have of urban blues therefore predate those of rural blues, but these songs are much more sophisticated, often on the borderline between an archaic and popular musical genre such as rural blues and a more modern and sophisticated one: jazz.

Bessie Smith Louis Armstrong St Louis Blues

Besides indicating a very large repertoire, the term blues has other, more technical and specific meanings. In particular, there is a blues musical scale, and a blues musical form, also known as a 'blues changes'. Let's delve into both.

The blues scale

The blues scale is a scale of African origin and is used not only in the blues repertoire, but also in other musical genres of the African-American tradition such as gospel, spirituals and work songs.

What distinguishes these various sub-genres is often the content of the lyrics, rather than specific musical elements. The gospel is religious music, the spiritual is often related to the tragedy of deportation, the work song is a labour song. The blues scale has also been used in more recent musical genres such as jazz, rock'n'roll, pop and even progressive rock.

While the origin of the blues scale is thus clear and is tied to the blues repertoire, it is nevertheless frequently found in musical genres far beyond the blues. The blues scale has become a musical scale 'like any other', which any composer can use even outside its native context.

The blues scale is very similar to the pentatonic scale, from which it is derived. More specifically, the blues scale is derived from the minor pentatonic scale, to which some passing notes, called blue notes, are added. In the score below you can see the pentatonic scale on the left, and the blues scale on the right with the passing notes, or blue notes, highlighted.

Pentatonic minor scale and blues scale

These passing notes are often performed as glissando by the voice and wind instruments, a technique that however cannot be reproduced on some instruments, e.g. the piano.

Guitar bluesmen, protagonists of what we have called rural blues, often used a piece of a broken bottle, a bottle neck, to play the glissando on the guitar. This specific technique is called slide.

The extended blues scale

The simplest and most common blues scale consists of seven notes: the five notes of the pentatonic scale, plus two blue notes. There is also a more extended blues scale that includes the notes of the major pentatonic and minor pentatonic scales, plus the two blue notes. In this way, the blues scale almost incorporates the sounds of the chromatic scale.

Scala pentatonica maggiore e minore
Major (left) and minor (right) pentatonic scales
The extended blues scale includes the notes of the two pentatonic scales, plus the two blue notes (in yellow)

Let us now move on to analyse the third and final meaning of the word blues: the musical form of 12 measures, also known as the blues changes, blues progression or 12-bar blues.

12-bar blues, or blues changes

The twelve-measure blues progression already existed in rural blues, yet singers accompanying themselves on guitar had no particular reason to strictly adhere to its duration.

Since they did not interact with other musicians and often improvised part of the text, it was normal for them to adapt the duration of the chords to the sung phrases, prolonging or shortening the duration of each stanza according to the needs of the poetic text.

In urban blues recordings, on the other hand, the twelve measure form is more rigorous than in rural blues. The band was in fact made up of several musicians who needed to play together, and therefore needed to know the duration of the stanzas in advance.

Piano Blues

The chords of the blues changes

Whether or not it respects the exact duration of 12 measures, the blues progression is characterised by three chords, the three major chords that we can derive from any major scale on degrees I, IV and V. For example, a C major blues uses the chords of C, F and G.

These three chords usually characterise four measures each, so the first four measures are based on the I degree chord, the next four measures on the IV degree chord and the final four measures on the V degree chord, which again prepares the first degree.

The blues is in fact a strophic and repetitive form: at the end of one blues cycle, another follows that is similar or the same in melody and harmony, while the lyrics change. The lyrics therefore unfold in a long series of blues verses, alternating between sung stanzas and instrumental ones.

Another characteristic of the blues is the tendency to play all the chords as dominant chords, thus as major chords with a minor seventh. The three chords of a C blues thus become C7, F7, G7. This contradicts the rules of tonal music, since the I, IV and V degrees of the major scale produce the chords Imaj7, IVmaj7, V7, and not three dominant chords.

This peculiarity of the blues can be explained by its hybrid nature: the blues began as modal music, based on the blues scale, and only later evolved towards tonal music through jazz musicians' elaborations. If you are interested, you can learn more about this topic in the lesson on the difference between modal and tonal music.

Text and melody in the blues

The text of a blues often follows a tripartite form, according to the pattern proposal - proposal - response. The text proposes a concept on the first four measures, thus on the I degree chord. The same text, and sometimes the same melody, is then repeated in the next four measures, on the IV degree chord. Finally, the answer occurs in the last four measures, on the V degree chord.

Often in the first sentence, the blues presents a conflict, a difficulty. In the second sentence, the same concept is reiterated in a similar or equal manner. Finally, in the third sentence, there is a solution, or at least an advancement of the story.

First sentence (bars 1-4)I degreeproposal
Second sentence (bars 5-8)IV degreeproposal
Third sentence (bars 9-12)V degreeresponse

Here is an example of a traditional song entitled Good Morning Blues. We observe that the first phrase "Good morning blues, blues how do you do?" is repeated twice, while the last four measures "answer" the question, and carry the story forward.

Good-Morning-Blues, un classico giro di blues
A traditional blues, Good Morning Blues

Here is a summary of the main features of the blues progression

  • Frequently, the blues have a duration of 12 measures. Archaic forms can be sometimes 8 measures, 16 measures, or they have a free form.
  • It is based on three major chords, the chords of the I, IV and V degrees of a major key.
  • It is tripartite from a melodic point of view and often also in the lyrics, following the sequence proposal - proposal - response.
  • It has a strophic form, each piece of music consists of numerous blues cycles, which musically are the same or very similar, but are used to tell the story (the lyrics).
  • Blues is' modal music, using dominant chords on the three degrees I, IV and V, which would be impossible in the context of tonal music.

We will now see how the 'blues changes' have been reinterpreted and enriched by jazz musicians.

The blues changes among jazz musicians

The blues progression was widely used by jazz musicians, who found it particularly good for improvisation. A strophic form that always repeats itself leaves great freedom to a musician engaged in an improvised solo. Twelve measures pass quickly and it is virtually impossible to get lost, and the blues scale is also very powerful and incisive.

Jazz musicians have developed the classic twelve-measure blues in multiple directions, doubling it into 24-measure stanzas, condensing it into 8-measure stanzas, inserting more or less complicated passing chords, creating tonal versions of it, and finally creating a minor version where the sequence I IV V is respected but using three minor chords.

Here are some examples of blues created by jazz musicians, elaborating on the classic 12-bars blues changes.

  • Blues For Alice by Charlie Parker. Tonal blues, with plenty of II V cadence movements.
  • Stolen Moments by Oliver Nelson. Blues in minor mode.
  • Watermelon Man by Herbie Hancock, 16 bar blues.
  • West Coast Blues, by Wes Montgomery. 24 bar blues in 3/4 time.
  • Bluesette by Toots Thielemans. 24 bar blues in 3/4 time, based on the harmony from Charlie Parker's Blues for Alice.
  • Footprints by Wayne Shorter. Minor blues, 3/4 time.

Jazz musicians have therefore elaborated the most typical blues changes in various ways, changing its duration, content or both. On this site you will find an analysis of several tunes, related to the blues repertoire in various ways. Here are some of them.

Conclusion, the many nuances of the blues

We have seen that the term 'blues' can refer to a music genre as a whole, with its vast world. Just as there are specialists in classical music, jazz, rock, there are blues specialists who only listen to and/or play the blues.

However, blues also indicates more precise and defined technical and musical elements: the blues scale, the blues changes. These should be known by any musician, even an amateur, who wants to try to play any kind of modern music. If you want some help with your studies, you might be interested in my private piano lessons.

In this article, we have seen how far the blues progression and the blues scale have come, starting from archaic or rural blues, but then contaminating jazz, rock, even electronic music, film music, songs.

I hope that this lesson will help clarify the different meanings of the word 'blues', but above all that it will arouse the curiosity to read, listen to, and keep playing new music. If you like, please leave a comment below. Thank you!

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