"Bang!" is a song by American pop band AJR. It was released on February 12, 2020, through their own label AJR Productions. The song is the lead single from the band's fourth album OK Orchestra.
AJR released their third studio album Neotheater on April 26, 2019. That fall, they embarked on an extensive North American tour in support of the album. Neotheater debuted to critical and commercial success, with album sales buoyed by the hit single "100 Bad Days". As a result, AJR announced the "Neotheater World Tour Part II" on November 15, 2019, with tour stops in North America, Europe, and South America, including festival appearances at Lollapalooza Argentina, Chile, and Brazil. The 2020 leg of the tour was postponed indefinitely due to the COVID-19 pandemic. AJR began working on "Bang!" in the process of writing Neotheater, and continued to work on the song throughout the subsequent tour. After struggling with how to make "Bang!" "sound current", the band sidelined the song to finish Neotheater, only returning to it after they finished touring.