For me, just seeing the mention of Son House stirred a memory. I do hope I've not told this story before but, if I have, I apologise and hope it's worth the repetition.
I saw Son House on 25 July 1965 at a festival in Rhode Island. He was on the bill for a late morning concert and the weather was dull. Son House came on stage with his steel guitar and, as he was playing "This little light of mine, I'm gonna let it shine", the sun really did come out and, as he played, it flashed off the polished steel. The sun mostly stayed out for the afternoon concert that day but clouds were beginning to come across. On the bill that afternoon were Richard and Mimi Farina. In the middle of their set, the clouds opened and, for a short while, buckets of rain fell out of the sky. But the crowd was not cowed by a summer squall and got off their feet and clapped and danced along to the music, defying the storm. And what was one the songs they played in their set? "Celebration for a Grey Day". Sometimes, music is just plain magical.