Someone posted about the Celtic Women version of Amazing Grace earlier. That reminded me of perhaps the most stirring version of that song. It comes at the end of the move "Amazing Grace" which is the story of William Wilberforce. The song itself was written by John Newton a former slave ship captain who became an advocate for abolition after a radical encounter with God. John was a mentor and significantly influenced Wilberforce, inspiring him to lead the fight for abolition in Parliament. BTW it is an excellent move, if a little uncomfortable to watch at times.
It starts with one set of bagpipes and swells from there. Very moving, especially if you have Celtic blood in your veins.