Historically, along the African coast, there was a requiem-like cadence in all their songs, while at work or paddling their canoes to and from shore, they kept time to the music. On Southern plantations, it was heard also, and in the African melodies everywhere, plaintive, and melodious, sad, and earnest. African workers, both in Africa and in America, were widely noted to sing while working. European observers found African work-singers remarkable because work songs were foreign to European culture. Such references begin to appear in the late 18th century, where the cliché is seen developing that Africans "could not" work without singing. For example, an observer in Martinique in 1806 wrote, "The negroes have a di!erent air and words for every kind of labor; sometimes they sing, and their motions, even while cultivating the ground, keep time to the music."\
So, while the depth of the African American work song tradition is now recognized, in the early 19th century this music stood in stark contrast to the rarity of such traditions among European Americans. Thus, while European sailors had learned short chants to use for certain kinds of labor, the paradigm of a comprehensive system of developed work songs for most tasks was contributed by the direct involvement of or through the imitation of African Americans. The improvisatory singing and community participation commonly found in African music produced call and response and repetitive chorus structures. It also encouraged individual expression, where singers freely injected utterances, and varied vocal timbres to produce groans, shrills, moans, wails, and screams that convey emotions and sounds of everyday life. Additionally, this approach produced verses harmony, the simultaneous rendering of slightly di!erent versions of the same melody by two or more performers. The centrality of dance in music-making activities established the hierarchy of rhythm over melody and the dominance of polyrhythmic structures, i.e. the layering of contrasting rhythms.