With regard to the etymology of the word "jook", see also this comment written by Lynn Fauley Emery in that same above mentioned book on Black dance:

"Despite the ban of the church and the chagrin of the civic leaders [in the 1900s], the Negro continued to dance. Segregated public dance halls developed throughout the South. There also developed a peculiar institution called the jook, or jook house. Jook is the anglicized pronunciation of "dzugu", a word from the Gulluh dialect of the African Bambara tribe meaning "wicked". Jook came to mean a Negro pleasure house: either a "bawdy house or house for drinking and gambling. It was in these jooks that "the Negro dances circulated over the world" were created. Before being seen on the stage by the outside world, these dances made the rounds of the Southern jooks."

Source-Zora Neale Hurston, "Mimicy", in Nancy Cunard, Negro Anthology (London: Wishard and Co; 1934); p.44

Emery also adds this comment to the note about the Black Bottom and other "Negro dances"-"Music in the jook houses was frequently provided by a large, gaudily decorated, coin-operated phonograph; hence the origin of the term juke-box".