Halsey amassed a cult of fans online and achieved pop ubiquity with her co-starring role on The Chainsmokers’ “Closer”. Her second album examines love up close while whirling through fussy electro-pop, trap-tinged brooding and shimmering ballads. The jittery “100 Letters” vibrates with self-laceration, its stuttering guitars playing counterpoint to Halsey’s wrenching vocal; Fifth Harmony’s Lauren Jauregui drops by for “Strangers”, a sumptuous portrayal of relationships rooted in alienation. Halsey’s hyper-diaristic lyrics put love, lust, betrayal and regret through the Instagram-filtered ringer on hopeless fountain kingdom, a comment on Tinder-era courtship that doubles as a daring exploration of pop.