They've appeared on stage once before, and at the time it was a career moment for Jelly Roll. He was no less hyped about it the second time. Jelly was playing a show in Detroit over the weekend as part of Post Malone's "Big A** Tour." So, while it was a surprise, it wasn't a huge surprise when he broke into Eminem's "Lose Yourself" for Em's hometown crowd. What was more of a surprise was when Slim Shady himself joined him to finish out the song. The Detroit crowd went wild, and rightfully so. As he left the stage, JR told the crowd, "If you can’t tell, that was a childhood dream come [ ] true, Detroit. This is the greatest show I’ve ever had in my [ ] life."