After slavery was abolished, together with the end of civil wars, army bands were dissolved and their musical instruments dumped. The wooden instruments were far too expensive and therefore not affordable for ex slaves. These new Afro-Americans had less to spend, however could afford the cheaper ones; the brass-instruments.

During that time period, street-bands were formed with as a base the T-bass and washboard. In addition, they played Brass-instruments, banjo, drum, and used their voice accompanied by handclaps.

The T-Bass was a cheap alternative for the wooden classical counter-bass and later the standing bass. It was made out of a tin tub, steel wire and a broomstick.
Washboards were used together with metal finger-hoods.
The prototype of the banjo was a calabash, or hollowed-out pumpkin, over which an animal skin was stretched and strings added.

Brass-instruments were those dumped army instruments; trumpet, cornet, trombone, tuba and for the more fortunate people; the saxophone. For drums, well, we don’t have to explain that, right?

Fretless 19th Century Banjo Source:

The voice and handclap were also used in a different way:

During times of slavery, a group of slaves would form a circle within their middle a foreman and lyrics were recited at a rhythmical base. This circle, was called a ring and the foreman was called a ring-shouter.
Shouting out lyrics, accompanied by handclaps, the cadans of “call and answer” was born: the work song.

For an example of a Ring-shouter, you can view a video at you-tube  of a group of singers, who still perform the original ring-shouting today:

The handclap was performed at a specific 4/4 beat, which means at 2nd and 4th beat, also known as the after-beat.

Short Tutorial

Focusing at these light beats during the cadans, the so called ‘chain-gang work song’ developed. Although slaves were (supposed to be) free at the beginning of the 20th century, life was still hard and work though for the new Afro-Americans and these work songs were still used as relief.