 <translate> To answer this question, we should know that: When the shooting began, country music singer Jason Aldean was giving the closing performance in front of an audience of about 22,000.
So, the answer is country music singer Jason Aldean. <yor> Láti dáhùn ìbéèrè yìí, ó yẹ ká mọ̀ pé: Nígbà tí wọ́n bẹ̀rẹ̀ sí yìnbọn, Jason Aldean tó jẹ́ olórin orílẹ̀-èdè kan ló ń kọ orin tó kẹ́yìn níwájú àwọn èèyàn tó tó ẹgbẹ̀rún méjìlélógún [22,000]. Nítorí náà, ìdáhùn náà ni olórin orin ilẹ̀, Jason Aldean. 