work a crowd

　大谷翔平選手がアナハイムのエンゼルススタジアムで入団会見を行いました。

Angels welcome Ohtani, plot course for 2-way Japanese star

A lively crowd gathered in front of Angel Stadium cheered when Ohtani donned a red No. 17 jersey and hat on stage with team owner Arte Moreno, manager Mike Scioscia and Eppler.
Ohtani doesn't speak much English yet, but he stepped to the podium and addressed the fans confidently: "Hi. My name is Shohei Ohtani."
Ohtani already knows how to work a crowd, too: He had the perfect answer when asked whether he was more excited to get his first pitching victory or his first homer in the big leagues.

http://www.asahi.com/ajw/articles/AJ201712100017.html

　“work a crowd”を取りあげます。「働く、動く」などと訳しがちな“work”ですが、LDOCEを見ると“if an entertainer or politician works a crowd of people, they entertain them and get their interest or support”とあります。『ジーニアス英和辞典』（第五版、大修館書店）では「（人）を次第に…の状態にする(into)；（人）を楽しませる、（人）の心をつかむ」と記載されており「群衆の心をつかむ」場合は記事のように“work a crowd”で表せることがわかりました。
例文に“work the crowd (up) into a frenzy”や“work oneself (up) into a rage”と挙げられているように“into ○○”で「状態にする」として使われます。(flying bird)