A favorite in the evening song circles on the poop deck where the folk pirates were forced to gather was based on the old French round, "Frere jacque". A common variation was: Aaarrrghh ya sleepin', Aarrrggh ya sleepin', Davey Jones, skull and bones. Hang 'em from the topsail, Heave 'em from the forecastle. Walk the plank, walk the plank. It was typically sung in three parts harmony, one part rum although sometimes the rum had a bigger part. On the whole these groups tended to consider absolutely everything to be public domain and therefore free for them to appropriate, inappropriate as that may seem today. Among the black pirates (i.e. pirates with higher levels of melanin beneath their skin, for the case could be made that all pirates were "black" in a different sense not referring to their pigmentaition of facial hair) the old spiritual "Steal Away" had a loyal following. The words were often spontaneously modified to reflect the loot d'jour (from: "A Jib and a Jab, Freelancing on the High Seas", 1923, Okrakoke Press).   Some pirate songs were collected as recently as the late 20th century before it was all over. Once scurrilous crew known as the Lincoln Park Pirates (as far as I can tell there is no known connection to the aforementioned Pirates from Pittsburg)beginning with "Way, hey haul them away," a line that could have come from 19th century shanties. Their song contained a fair amount of braggadacio and refers to a possible hideout from which they took their name, The Lincoln Park Lagoo-in (possibly "lagoon")(S Goodman, aural communication)