I recorded the show, certainly am a Sharpe's fan, and the singing has always been a big part of it. I didn't watch the credits but it still sounds like John Tams, and that damn' O'er the hills and o'er the plains, to Flanders, Portugal.... has been going through my head ever since I watched it last night. But John Tams character, Rifleman Hagman was killed off a while back.
There was that song, and there was the very familiar, Now I'm off to India for seven long years, but the other one -- I'll listen again and in the meantime hope someone more knowledgeable will jump in with title, etc.
Good show, though!