Here's some timely movie trivia: All of those Southpaw images featuring a ripped-out-of-his-mind Jake Gyllenhaal that you've seen online and in TV spots were, at one time, meant to be of a ripped-out-of-his-mind Eminem.

When it was first announced in late 2011, the boxing drama Southpaw, directed by Antoine Fuqua (Training Day), was supposed to star Marshall Mathers, who would’ve made a long-overdue acting comeback following his subtly excellent performance in 2002’s kinda-biopic 8 Mile. The script, written by Sons of Anarchy mastermind Kurt Sutter, was ready for Eminem, but the iconic rapper got cold feet once it came time to start prepping his eighth solo album, The Marshall Mathers LP 2 (which was released in November 2013). Left without a leading man, Southpaw’s producers met with Aaron Paul (Breaking Bad) and Charlie Hunnam (Sons of Anarchy) before landing on Gyllenhaal for the role of Billy Hope, a boxing champ who’s pulled back into the ring after a family tragedy rocks his world.

Genuinely a fan of the project, Eminem stuck around to what he does best: he oversaw the film’s music. Southpaw's original soundtrack drops this week via Em’s Shady Records, and features new songs from 50 Cent (who also co-stars in Southpaw as a fight promoter), Slaughterhouse (Joe Budden, Royce Da 5’9, Crooked I, Joell Ortiz), PRhyme (Royce Da 5’9 and DJ Premier), D12 member Denaun and appearances from rap heavyweights Busta Rhymes and Tech N9ne. There are also two new Eminem tracks: "Phenomenal" and the Gwen-Stefani-assisted "Kings Never Die."

In today’s record industry, the Southpaw soundtrack is comparable to Haley’s Comet. Once a common practice, compilation albums loaded with original tracks from popular hip-hop artists have fallen out of popularity, at least within the music biz; blame it on the decline of record sales, which doesn’t exactly justify the costs required to assemble a substantial "who's who of rap and R&B" lineup on one gargantuan release. Back in the '90s and early 2000s, though, new hip-hop-centric movie soundtracks were hitting shelves on what seemed like a monthly basis, yielding some of urban radio's best jams and catering to every kind of hip-hop listener.

Bet you didn’t realize that without 1999’s In Too Deep soundtrack, for example, 50 Cent might not even have a career, huh? Or that Warren G and Nate Dogg’s timeless "Regulate" happened because of a Tupac Shakur movie? Those are just two of the audio flashbacks you’ll hear in this: The Ultimate Hip-Hop Movie Soundtrack Playlist. Use it to feel all nostalgic or to DJ all future summer barbecue parties.

For a breakdown of which songs here appeared on which soundtracks, see the above slideshow.