Groaners

The Groaner - a deep rasping male singing style, and about as far from Bing Crosby as you can get -  features in quite a few African and Afro-derived musical styles. Here's the South African Mahlathini with the Mahotella Queens:

The reggae groaner was "The Voice of Thunder" Prince Far I (a man with whom I once shared a joint, but perhaps that's a story for which the world is not yet ready). There's a short clip of the man in action here, otherwise it's singles like Wisdom, or Throw Away Your Gun (sad, given his death from shooting in 1983) and the extraordinary Rastafarian Deck of Cards (if you get a pub quiz question about the connection between Wink Martindale and Prince Far I, well, now you know).

As for the US, well, quite a few blues singers had rough dark voices - Howlin' Wolf would be the obvious example - but no one came close to Blind Willie Johnson, here with John the Revelator.

They're all dead now (Mahlathini died in 1999). It'd be a shame if the tradition had died out with them. Is that kind of hyper-masculine style seen as too crude or offensive nowadays?