Origins Of The Blues

Little is known about the exact origins of the music we now know as the blues. No specific year can be cited as the origin of the blues, largely because the style evolved over a long period of time and existed in something approaching its modern form before the term blues was introduced, before the style was thoroughly documented. One important early reference to something closely resembling the blues comes from 1901, when an archaeologist in Mississippi described the songs of black workers which had lyrical themes and technical elements in common with the blues. The most important direct antecedent of the blues was the spiritual, a form of religious song with its roots in the camp meetings of the Great Awakening of the early 19th century. Spirituals were a passionate song form, that "convey(ed) to listeners the same feeling of rootlessness and misery" as the blues. Spirituals, however, were less specifically concerning the performer, instead about the general loneliness of mankind, and were more figurative than direct in their lyrics. Despite these differences, the two forms are similar enough that they can not be easily separated — many spirituals would probably have been called blues had that word been in wide use at the time.
Blue Note
In jazz and blues, blue notes are notes sung or played at a lower pitch than those of the major scale for expressive purposes. Typically the alteration is a semitone or less, but this varies among performers. Country blues, in particular, features wide variations from the tonic but still with the blue-note feeling.

The blue notes are usually said to be flattened third, flattened fifth, and flattened seventh scale degrees, although they approximate pitches found in African work songs. These blue notes are what turns a major scale into the blues scale. The same transformation of notes transforms the minor scale into the minor blues scale, as heard in songs such as "Why Don't You Do Right?".

The blues scale is used in almost all twelve-bar and eight-bar blues, but it is also used in blues ballads and in conventional popular songs with a "blue" feeling, such as Harold Arlen's "Stormy Weather".

In its earliest manifestations, the flattened third, or mediant, and flattened seventh, or subtonic, were the main blue notes.