This is a fakebook style arrangement in that it has the lyrics and melody on the top staff and the banjo back-up and solo on the 2nd and lower staff providing harmony support to the amazingly beautiful traditional English melody.
As an added bonus, there is a simple mandolin solo that plays simultaneously with the banjo support...
This arrangement is in the key of C.
I think it's a fairly simple arrangement, but it does require some up-the-neck chord work for the banjo.
Tom