One Direction’s fourth album finds the band at a crossroads: attempting to push against the musical restrictions of being one of the biggest bands in the world without losing their appeal. So out goes the joyous sugar rush of their early singles (even lead single “Steal My Girl” feels relatively muted), replaced instead with the contemplative slow burn of the lovely “Night Changes” and the Ed Sheeran-assisted “18.” There's still youthful exuberance (the lustful “Girl Almighty”), but this more pensive, thoughtful side suits them well.