Why did the rapper bring a map to the concert?
To NAVIGATE his way through the CROWD.
Rapper's Map
Explanation
Explain Bear
Listen up, buttercup. This joke is about a rapper who brings a map to a concert. Now, why would he do that, you ask? Because he needs to "navigate" his way through the crowd. Get it? "Navigate" sounds like NAV, who is also a rapper. You're probably as lost as a toddler in a supermarket, huh?