There are a number of different ideas as to what the blues really are: a scale structure, a note out of tune or out of key, a chord structure; a philosophy? The blues is a form of Afro-American origin in which a modal melody has been harmonized with Western tonal chords. In other words, we had to fit it into our musical system somehow. But, the problem was that the blues weren't sung according to the European ideas of even tempered pitch, but with a much freer use of bent pitches and otherwise emotionally inflected vocal sounds. These 'bent'pitches are known as 'blue notes'. The 'blue notes' or blue tonalities are one of the defining characteristics of the blues. Tanner's opinion is that these tonalities resulted from the West Africans' search for comparative tones not included in their pentatonic scale. He claims that the West African scale has neither the third or seventh tone nor the flat third or flat seventh. "Because of this, in the attempt to imitate either of these tones the pitch was sounded approximately midway between [the minor AND major third, fifth, or seventh], causing what is called a blue tonality." When the copyists attempted to write down the music, they came up with the so-called "blues scale," in which the third, the seventh, and sometimes the fifth scale-degrees were lowered a half step, producing a scale resembling the minor scale. There are many nuances of melody and rhythm in the blues that are difficult, if not impossible to write in conventional notation. But the blue notes are not really minor notes in a major context. In practice they may come almost anywhere.

         American troops brought the blues home with them following the First World War. They did not, of course, learn them from Europeans, but from Southern whites who had been exposed to the blues. At this time, the U.S. Army was still segregated. During the twenties, the blues became a national craze. Records by leading blues singers like Bessie Smith and later, in the thirties, Billie Holiday, sold in the millions. The twenties also saw the blues become a musical form more widely used by jazz instrumentalists as well as blues singers.During the decades of the thirties and forties, the blues spread northward with the migration of many blacks from the South and entered into the repertoire of big-band jazz. Before the field cry, with its bending of notes, it had not occurred to musicians to explore the area of the blue tonalities on their instruments. The early blues singers would sing these "bent" notes, microtonal shadings, or "blue" notes, and the early instrumentalists attempted to duplicate them. By the mid-twenties, instrumental blues were common, and "playing the blues" for the instrumentalist could mean extemporizing a melody within a blues chord sequence. Brass, reed, and string instrumentalists, in particular, were able to produce many of the vocal sounds of the blues singers. BLUES LYRICS Blues lyrics contain some of the most fantastically penetrating autobiographical and revealing statements in the Western musical tradition. For instance, the complexity of ideas implicit in Robert Johnson's 'Come In My Kitchen,' such as a barely concealed desire, loneliness, and tenderness, and much more:You better come in my kitchen, It's gonna be rainin' outdoors.Blues lyrics are often intensely personal, frequently contain sexual references and often deal with the pain of betrayal, desertion, and unrequited love or with unhappy situations such as being jobless, hungry, broke, away from home, lonely, or downhearted because of an unfaithful lover.

         The blues also became electrified with the introduction of the amplified guitar. In some Northern cities like Chicago and Detroit, during the later forties and early fifties, Muddy Waters, Willie Dixon, John Lee Hooker, Howlin' Wolf, and Elmore James among others, played what was basically Mississippi Delta blues, backed by bass, drums, piano and occasionally harmonica, and began scoring national hits with blues songs. At about the same time, T-Bone Walker in Houston and B.B. King in Memphis were pioneering a style of guitar playing that combined jazz technique with the blues tonality and repertoire. The early blues were very irregular rhythmically and usually followed speech patterns, as can be heard in the recordings made in the twenties and thirties by the legendary bluesmen Charley Patton, Blind Lemon Jefferson, Robert Johnson and Lightnin' Hopkins among others. The meter of the blues is usually written in iambic pentameter. The first line is generally repeated and third line is different from the first two. The repetition of the first line serves a purpose as it gives the singer some time to come up with a third line. Often the lyrics of a blues song do not seem to fit the music, but a good blues singer will accent certain syllables and eliminate others so that everything falls nicely into place. The structure of blues lyrics usually consists of several three-line verses. The first line is sung and then repeated to roughly the same melodic phrase (perhaps the same phrase played diatonically a perfect fourth away), the third line has a different melodic phrase:I'm going to leave baby, ain't going to say goodbye. I'm going to leave baby, ain't going to say goodbye. But I'll write you and tell you the reason why.

         In the early nineteen-sixties, the urban bluesmen were discovered by young white American and European musicians. Many of these blues-based bands like the Paul Butterfield Blues Band, the Rolling Stones, the Yardbirds, John Mayall's Bluesbreakers, Cream, Canned Heat, and Fleetwood Mac, brought the blues to young white audiences, something the black blues artists had been unable to do in America except through the purloined white cross-over covers of black rhythm and blues songs. Since the sixties, rock has undergone several blues revivals. Some rock guitarists, such as Eric Clapton, Jimmy Page, Jimi Hendrix, and Eddie Van Halen have used the blues as a foundation for offshoot styles. While the originators like John Lee Hooker, Albert Collins and B.B. King--and their heirs Buddy Guy, Otis Rush, and later Eric Clapton and the late Roy Buchanan, among many others, continued to make fantastic music in the blues tradition. The latest generation of blues players like Robert Cray and the late Stevie Ray Vaughan, among others, as well as gracing the blues tradition with their incredible technicality, have drawn a new generation of listeners to the blues.

CONSTRUCTION OF THE BLUES:
         Most blues researchers claim that the very early blues were patterned after English ballads and often had eight, ten, or sixteen bars. The blues now consists of a definite progression of harmonies usually consisting of eight, twelve or sixteen measures, though the twelve bar blues are, by far, the most common.The 12 bar blues harmonic progression (the one-four-five) is most often agreed to be the following: four bars of tonic, two of subdominant, two of tonic, two of dominant, and two of tonic. Or, alternatively, I,I,I,I,IV,IV,I,I,V,V,I,I. Each roman numeral indicates a chord built on a specific tone in the major scale. Due to the influence of rock and roll, the tenth chord has been changed to IV. This alteration is now considered standard. In practice, various intermediate chords, and even some substitute chord patterns, have been used in blues progressions, at least since the nineteen-twenties.Some purists feel that any variations or embellishments of the basic blues pattern changes its quality or validity as a blues song. For instance, if the basic blues chord progression is not used, then the music being played is not the blues. Therefore, these purists maintain that many melodies with the word "blues" in the title, and which are often spoken of as being the blues, are not the blues because their melodies lack this particular basic blues harmonic construction. I believe this viewpoint to be a bit wide of the mark, because it places a greater emphasis on blues harmony than melody.

         The principal blues melodies are, in fact, holler cadences, set to a steady beat and thus turned into dance music and confined to a three-verse rhymed stanza of twelve to sixteen bars. The singer can either repeat the same basic melody for each stanza or improvise a new melody to reflect the changing mood of the lyrics. Blues rhythm is also very flexible. Performers often sing "around" the beat, accenting notes either a little before or behind the beat. Jazz instrumentalists frequently use the chord progression of the twelve-bar blues as a basis for extended improvisations. The twelve or sixteen bar pattern is repeated while new melodies are improvised over it by the soloists. As with the Baroque bassocontinuo, the repeated chord progression provides a foundation for the free flow of such improvised melodic lines.

CONCLUSION
         One of the problems regarding defining what the blues are is the variety of authoritative opinions. The blues is neither an era in the chronological development of jazz, nor is it actually a particular style of playing or singing jazz. Some maintain (mostly musicologists) that the blues are defined by the use of blue notes (and on this point they also differ - some say that they are simply flatted thirds, fifths, and sevenths applied to a major scale [forming a pentatonic scale]; some maintain that they are microtones; and some believe that they are the third, or fifth, or seventh tones sounded simultaneously with the flatted third, or fifth, or seventh tones respectively [minor second intervals]). Others feel that the song form (twelve bars, one-four-five) is the defining feature of the blues. Some feel that the blues is a way to approach music, a philosophy, in a manner of speaking. And still others hold a much wider sociological view that the blues are an entire musical tradition rooted in the black experience of the post-war South. Whatever one may think of the social implications of the blues, whether expressing the American or black experience in microcosm, it was their "strong autobiographical nature, their intense personal passion, chaos and loneliness, executed so vibrantly that it captured the imagination of modern musicians" and the general public as well.