The Blues are an expression of the heart. The Blues are not about a formula, chords, or a style. They are about the destruction of this life. Putting ones heart into something greater. They are about a hope, greater than the things of this world. Sorrow for the things of this world.
The only qualification one must have to sing the blues is: To have lived the blues. To have come to the point in their life that nothing in this life can bring happiness. It's when a person evolves into an unselfish love that brings happiness and fulfillment that this life cannot. It's singing about the truth of this life and it's end is death and destruction...always. It's a point where people seperate...either evolve, or turn into a complete destroyer. The evolved sing the blues.
When a person speaks of the Blues from the point of view of formulas, style, chords, etc. They do not yet have a clue. They have not lived the Blues.
"It's not a performance...It's an experience." ...Janis Joplin