The title is no idle boast: Demi Lovato’s fifth album is their most assured. Enlisting master craftsmen of 21st-century pop such as Max Martin, Stargate and Ryan Tedder, they've built a collection of sparkling, hip-hop-laced electro-pop that’s impressively punchy in tone and melody. Self-empowerment is the motif as Lovato chews up haters (“Waitin for You”), chases sexual adventure (“Cool for the Summer”) and confronts heartbreak and grief on gale-force ballads “For You” and “Father”.