LL Cool J and Brad Paisley sparked quite the controversy with their uncomfortable duet, "Accidental Racist," but when it comes to ill-advised collaborations, the country/rap hybrid is far from the worst. Over the years, we've seen everyone from Sting and Twista to Hilary Duff and Slim Thug link up in the name of music. We're all for taking risks and defying expectations, but mixing genres can definitely result in tragic consequences. Case in point: The 20 Most Awkward Music Collaborations. Read on and listen to what happens when people like Ja Rule and Metallica get on a track together. You're going to wish that these songs never happened.