Scarborough Fair, sung by Yorkshire lead miner mark Anderson made it as far as 'The Graduate' - Don't suppose his family saw too much of the royalties
For me, the best use of traditional songs for movies was John Tams use of field recordings for the superb but now virtually unobtainable (I've tried) 'Ill Fares the Land', about the evacuation of St Kilda
Songcatcher was another great, and the use of field recordings by Pasolini for both 'The Decameron and 'Te Arabian Nights' - exquisite
Jim Carroll