Early Styles (Musicians Active before 1930)
Early Country Blues
Early Urban Blues
Early Jazz Blues
Kansas City Blues
Later Styles
Post War Jazz Blues
Chicago Blues
Modern Blues (post 1950s)
Blues in conventional pop music
... square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...