(AllHipHop News) Rappers Eminem and Jay-Z kicked off a four-date tour last night (September 2nd) at Detroit's Comerica Park. Over 40,000 people filled the stadium to catch a glimpse of the two famous rappers, who are doing two shows at Comerica Park and another two in New York at Yankee's Stadium on September 13th and 14th. Atlanta rapper B.o.B. opened the show, with a half-hour set, flanked by the huge video set that takes a crew of about 300 to set up. Jay-Z was dressed in all black, and performed a medley of his best known hits, including "Big Pimpin," "Forever Young" and "Hard Knock Life," with the help of longtime associate, Memphis Bleek and a guest appearance from Atlanta rapper Young Jeezy.After an hour-long set, Jay-Z labeled the experience as "one of the best experiences" of his "entire life."Eminem hit the stage shortly after Jay-Z, around 10:40PM and gave an energetic set of songs like "Won't Back Down," "Kill You" "Cleaning Out My Closet" "Lose Yourself" and others. During his set, which included a live band and The Alchemist as a DJ, Eminem brought out Trick Trick, D12, Drake, Lloyd Banks, 50 Cent and Dr. Dre, who promised fans that his highly anticipated album Detox "is coming.""I'm so motherf**king happy to be back," an excited Eminem told his fans. According to reports, Rihanna and Lady Gaga are expected to hit the stage during tonight's (September 3rd) show.