Way back. Then even further.
When you read the materials, you see 200 years of the same: "Details on Juba's early life are scarce. As a teenager, he began his career in the rough saloons and dance halls of Manhattan's Five Points neighborhood." Might as well be talking about Chris Wallace.
In the mean time:"Many of the songs were adapted to popular melodies in well known operas..." Sounds like the brothers were sampling, to us.
