@ Gordon Jackson: have you ever seen Fisherman's Friends on stage? They DON'T sing all of their songs a cappella; guitars and orher instruments very much in evidence, I too would prefer the unaccompanied versions of shanties.

Can't remember the name of the film now, but it was shown at the Scots Fiddle Festival a couple of years back: talking about 18th century musuc and playing Scott Skinner's "Hector the Hero": only a century out!