Trade Bangle from West Africa, from 1700-1800. It was probably used to promote a trader and his business.

http://www.bbc.co.uk/ahistoryoftheworld/objects/kUB_4NB-SxeWhXYP-hs81Q

http://incompetech.com/music/royalty-free/index.html?genre=African

http://www.state.gov/r/pa/ei/bgn/2836.htm

http://countrystudies.us/nigeria/

http://www.san.beck.org/16-10-WestAfricaBritish.html#a5