“SOS” is the first single from Avicii since his tragic passing on April 20, 2018. The track, which features Aloe Blacc, serves as the lead single for TIM, his posthumous third album. This marks Avicii and Aloe Blacc’s third collaboration, after “Wake Me Up” and “Liar Liar.” The track details some of Avicii’s personal battles, including drug usage and struggles with love, over a synth-heavy instrumental.

The song was teased in a YouTube video on April 5, 2019, promoting TIM.