Here are 10 items to help demystify "Django Unchained." If you know your stuff, feel free to share more nuggets of trivia in the comments.
Warning: this article contains mild spoilers.
The original "Django" isn't the only spaghetti Western referenced here. That 1966 movie is only one of several off-kilter examples of the genre directed by Sergio Corbucci; according to this article about Corbucci's films that Tarantino wrote for The New York Times, the filmmaker was also a fan of Corbucci's far more serious "The Great Silence," from 1968. Unlike the dusty landscapes that populate most Westerns, "The Great Silence" takes place in the wake of a blizzard that swept Utah in 1899, and so a blindingly white backdrop populates most scenes. In tribute, during a montage sequence in "Django Unchained" where the titular freed slave and bounty hunter Dr. King Schultz (Christoph Waltz) spend several months teaming up to take down various wanted men, they're seen riding around in a wintery setting.
Christoph Waltz is Tarantino's Klaus Kinski. The late German actor Kinski starred in a number of spaghetti Westerns, including "The Great Silence," which makes the presence of a German bounty hunter in the Old West of "Django Unchained" less random than it would otherwise seem.
Not every Corbucci reference is so overt. The movie is littered with Easter eggs acknowledging the filmmaker's oeuvre, some of which are extremely subtle. The saloon that Django and Dr. King visit in the first town they ride into is titled "Minnesota Clay," the name of a 1966 Corbucci Western starring Cameron Mitchell in the title role.
Mandingo fighting isn't a real thing, but it is a real film. When Django and Dr. King go to the Candyland ranch, they pretend to be experts in Mandingo fighting, which in Tarantino's world is a bloody sport. In fact, the word refers to Richard Fleisher's 1975 film about a plantation that trains slaves to fight each other.
Still, if you see one movie to prepare for "Django Unchained," make it the original "Django." The opening song (below) that plays over the credits for "Django Unchained" is directly lifted from Corbucci's "Django," which opens with the eponymous gunslinger dragging a coffin into town (blink and you'll miss another "Django" reference with the appearance of a coffin near the end of the movie). Even the typeface of the credits for "Django Unchained" culls from the original "Django." Finally, "Django" superstar Franco Nero shows up in a memorable cameo during the first scene at the Candyland plantation (when Leonardo DiCaprio's character makes his initial appearance). It's not much of a performance, but he does get to blatantly acknowledge his persona in an amusing exchange with Jamie Foxx.