Eminem surprised fans by dropping the deluxe edition of his most recent project, Music to Be Murdered By, on Friday (December 18) at midnight.

The “B-Side” project features 16 new tracks, including a track with Dr. Dre called Guns Blazing.” Dre also co-produced tracks “She Loves Me” and “Discombobulated.” Em also issued a heartfelt apology to Rihanna on “Zeus,” where he addressed a decade-old song that leaked last year where he said he was “siding with Chris Brown.” On “Zeus,” Em tells Rihanna, “And wholeheartedly apologies Rihanna for that song that leaked/I’m sorry, Rih, it wasn’t meant to cause you grief/But regardless it was wrong of me.”

The album also includes features from Skylar Grey, DJ Premier, Ty Dolla $ign, Dr. Dre, Sly Pyper, MAJ and White Gold.