Just to avoid confusion for anyone who has not heard one or the other, the tune MMario pointed to is, as it says, the one used in THE BEGGAR'S OPERA - but this is not the one used on PARCEL OF ROGUES.

I know the latter may not be any more real than any of the others, Mag, but it is incredibly well matched to the lyrics. I've hunted round but never found this version (short of forking out to the personalised service on offer via the Steeleye website). But it's a dead easy tune, so maybe I'l jot it down myself in the next few days, if someone doesn't turn up a definite sighting first.