Question about an ingredient (and a recipe)

So I saw this recipie on a menu and I'd like to try it out (I saw it online or I would have ordered it):bourbon, black currant, fresh lime, and ginger beer, served on the rocks, tallAnd I'm wondering a couple of things: for starters, is the "black currant" going to be muddled fruit or syrup or a liqueur? (Is there some basic ingredient that I could pick up or am I going to be experimenting in the kitchen this weekend?)Second, is this a variation on a known drink? If so, what? http://www.reddit.com/r/cocktails/comments/3ee88s/question_about_an_ingredient_and_a_recipe/