The Singing Wells
I knew nothing about Singing Wells but, thanks to the magic of the internet, we all do now!
The documentary, Photographing Africa, mentions the Singing Wells and a little judicious searching on the term unearthed this video from Ethiopia, this report from BBC Worldwide and this Facebook link to the music of East Africa. It seems that the work song rhythms help keep full buckets of water moving from the well and empty ones returning, sort of like the jobs that sea shanties are designed for. Hurrah for the Web!