Depends on the vibe you're going for. Something Arthurian or Celtic and things like Enya, Loreena McKennitt, Cirque du Soleil soundtracks, and a lot of trad Irish music would work. Or Celtic punk and Irish rebel songs if you're going harder. The Pogues, Wolfe Tones, Rebel Hearts, Dubliners, Flogging Molly, Dropkick Murphys, Sinead O'Connor, the Tossers, Clannad, that kind of thing.

But for something set in the Caribbean you'd want pirate soundtracks, Salsa, Rumba, Reggae, and a whole lot of Celia Cruz.