I recently discovered these amazing voices. The group is called GENTRI, and they tout themselves at the Gentleman Trio. Most of their material is inspirational. There is another member of the group who functions as their composer/arranger, which, in addition to their pure tenor voices, is what really makes their work stand out.
I could hear this song - One - in the entry courtyard area of the American Heartland Theme Park that should be under construction soon in Vinita, Oklahoma.