Blackface refers to the practice of a singer and/or comedian appearing as a black person by painting the face.
The practice originated as a performance tradition in America in the 1830s, quickly becoming popular globally, and would be most commonly associated with the minstrelsy tradition. Early white performers in blackface used burnt cork and later greasepaint or shoe polish to blacken their skin and exaggerate their lips, often wearing woolly wigs, gloves, tailcoats, or ragged clothes to complete the transformation. Later, black artists also performed in blackface. Variations of blackface performance are also found in a number of associated performance traditions, e.g. in the Mardi Gras tradition in the USA (see Staub, 1992) and the Coon Carnival in South Africa.
W.J. Mahar. 1999. Behind the Burnt Cork Mask: Early Blackface Minstrelsy and Antebellum American Popular Culture. Volume 442 of Music in American life. University of Illinois Press, 1999