For the soundtrack of Quentin Tarantino’s Django Unchained, the former 2Pac engineer Claudio Cueni pulled a Girl Talk, smashing Pac’s vocal from the posthumous throwdown “Untouchable” with James Brown’s “The Payback,” dialog clips from the movie, and triumphant spaghetti-western horns. The end result, entitled “Unchained” is an exhilarating mess, and you can hear it below. [...]