Two years ago, Halsey was an unknown pop singer who, with help from some online tastemakers, had a minor hit with New Americana, a sharp-tongued portrait of disaffected millennials.

Then she was the voice on The Chainsmokers' Closer, a smash hit around the world, and now she has her own No. 1 album. Her second album, Hopeless Fountain Kingdom (Astralwerks), opened at the top of the latest Billboard chart with 76,000 copies sold as a full album and 36.6 million streams of its songs in the United States, according to Nielsen.

Halsey's reign at the top will likely be short-lived. American singer Katy Perry's new album, Witness, was released last week and is likely to go straight to No. 1 on next week's chart.