Seeing musicians bring up fans to perform songs with them at concerts is always kind of a stressful moment. Will the fan deliver? Or will they flounder around on stage and make a fool of themselves? Kendrick Lamar's set last night at the Sweetlife Festival in Maryland had a bit of both. After the first fan embarrassed himself on the mic, Kendrick invited up a female audience member named Ayanna to do "m.A.A.d city" with him – and boy, did she do it right. Even with her voice getting hoarser as the song went on, she transformed from timid fan to stage-owning rap star in all of five seconds. The magic starts around the 5:20 mark. In Kendrick's own words from the end of the clip: "I say she killed that shit."