When composer Michael Tippett heard Alfred Deller singing in Canterbury Cathedral, he "felt the centuries roll back" - because he was listening to probably the first solo-quality male alto - or countertenor - since the time of Henry Purcell.
I had the analogous experience listening to Martin Carthy perform King Henry in the Gulbenkian Theatre, Newcastle University, in the late 1970s.
Go to 44:58The centuries rolled back and I was mentally transported to some medieval feasting hall, listening to the bard weave his magic - and it is indeed a magical ballad.
Which King Henry? - I don't know, but I imagine King Henry II (1154-89 - the one under whose rule Thomas Becket was martyred) - because it sounds like exactly the sort of thing he might have done...