Jazz was a product of the confrontation of two worlds. The African Negro, transported in slavery, took with him to his new land his native musical traditions, which were corporeally rhythmic and vocally modal; and these came into contact—and before long into conflict—with the harmonic conventions of the West (specifically those of the march and hymn). Out of this tension was generated the classic form of the blues, the traditional basis of jazz. During the first two decades of the twentieth century the black man in America created a music that expressed not only his powerful protest against dispossession, but also a nostalgia for ‘the beauty of his wild forebears’; and (which was more remarkable) the white man too came to recognize in the black man's music a vitality and spontaneity which he, in his modern self-consciousness, had lost.