Running Wild
Running Wild (http://en.wikipedia.org/wiki/Running_Wild_%28band%29) a long running Speed Metal (http://en.wikipedia.org/wiki/Speed_Metal)/Power Metal (http://en.wikipedia.org/wiki/Power_Metal) act from Germany (http://en.wikipedia.org/wiki/Germany) have utilized a piracy gimmick since the late 1980s, releasing albums and songs with names such as "Under Jolly Roger", "Port Royal", "Treasure Island", "Calico Jack", "Jennings' Revenge" (about the hugely successful 1715 pirate raid by Henry Jennings (http://en.wikipedia.org/wiki/Henry_Jennings)) and "Rogues en Vogue".


Swashbuckle: Crewed by the Damned
www.swashbuckle.info (http://www.bilgemunky.com/link.php?url=http://www.swashbuckle.info/)
"Their music is metal, true enough, but the lyrics - while still throaty growls - remain clear enough that anyone should have no problem understanding the "yo hos" and "bring on the wenches." But Swashbuckle goes one step further and mixes some traditional spanish guitar and other period sounds into their otherwise tough metal style."

A list with reviews of more is at http://www.bilgemunky.com/reviews/music/ covering all types, metal, steel drum, etc.

I recommend The Crimson Pirates - (http://www.crimsonpirates.com/). They perform a mix of a mix of sea shanties, sailing songs, Irish drinking songs and renaissance faire song standards and will be at the New York Renaissance Faire (http://www.renfair.com/NY/) again this year. They are also currently working on a new album, hopefully to be out this summer.

The Corsairs are another Fine Pirate band.

Captain Bogg and Salty (http://www.eatalime.com)

Great Big Sea does some good pirate songs as well. So do the Irish Rovers, and a few other traditional bands. Its becoming more popular.

Y'know, metal & pirates just never came together in my head, but that first band Bob mentioned sounds interesting.

Running Wild is, IMHO, one of the best bands ever. The guitars are crunchy, the vocals raw yet legible, and the lyrics often deep and complex. "Ballad of William Kidd" is a look at the infamous Captain Kidd, exploring his life, crimes and death. They've also covered the gambit of history during their career, including the Battle of Little Bighorn, Waterloo and the fall of the Tzar.