Levels was released by Swedish DJ Avicii in 2011 and became one of the defining dance tracks of the early 2010s, built around a vocal sample from Etta James. Its intro, with its steady build and instantly familiar melody, helped it cross from clubs and festivals into radio, commercials and online videos. Years after Avicii's death in 2018, the track remains a shorthand for euphoric electronic music, and creators still use its opening to signal energy, nostalgia and a big moment about to happen.